^^^mmiMsmmmmm^0m»mm U f^^K ALi.\A;i(=-e RR'D" s O Yt^'^^^'^'^'"^^^^^'^-^ L_\:::^aAC< ^ c Ouu I tvis ^e «- x-^ J iM i:\ Height s ani;. We IG-HT OF" CIAOOU c lA \ u, o r^ e v\/ Wa^H in gton 1 i \ ^^^.2. Class _4^ )3 ^n"^ Book ^/y^C TREASURY DEPARTMENT UNITED STATES PUBLIC HEALTH SERVICE HUGH S. GUMMING, Surgeon General HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN A STUDY OF THE HEIGHTS AND WEIGHTS OF 14,335 NATIVE WHITE SCHOOL CHILDREN IN MARYLAND, VIRGINIA, AND NORTH AND SOUTH CAROLINA BY TALIAFERRO CLARK Surgeon EDGAR SYDENSTRICKER Statistician AND SELWYN D. COLLINS Assistant Statistician United States Public Health Service REPRINT No. 750 FROM THE PUBLIC HEALTH REPORTS Mat 19, 1922 (Pages 1185-1207) ^^ -Lt^f^^^ WASHINGTON GOVERNMENT PRINTING OFFICE 1922 I i ADDITIONAL COPIES OF THIS PUBLICATION MAT BE PROCURED FROM ■ THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE "WASHINGTON, D. C. AT 10 CENTS PER COPY LIBRARY OFXONGRESS - NOV231922 ! DOCUMeNTS DlViSi). ^ HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. A Study of the Heights and Weights of 14,335 Native White School Children in Maryland, Virginia, and North and South Carolina.' By Taliaferro Clark, Surgeon; Edgar Sydenstricker, Statistician; ' and Selwyn D. Collins, Assistant Statistician, United States Public Health Service. Introductory. A number of so-called standards of the physical development of children are in more or less general use in this country, largely for determining the state of nutrition. For the most part these standards represent averages of measurements made by different observers in widely separated communities, without reference to racial stock or geographical distribution. For purposes of comparison and in order to present anthropometrical observations for groups that are fairly homogeneous with respect to race stock and geographic location in the United States, selections of records were made from a consider- ably larger amount of material collected in a series of field investi- gations in child hygiene by Public Health Service officers during the last six years. The present study deals with 14,335 white children of native parent- age in representative localities in Maryland, Virginia, and North and South Carolina. The observations are confined to children actually attending school, ranging in age from 6 to 16 years, inclusive. While in every case a somewhat intensive physical examination (and for a considerable proportion, mental examination) was made, all children regardless of their physical or mental status, were included. The observations, therefore, may be said to be of a typical school popu- lation within the racial and geographical limits mentioned; they in- clude the handicapped individuals, as far as handicapped individuals were found attending school, as well as the probable normal. A considerable variety of anthropometrical records was collected for each individual in addition to records of physical defects and men- tal status. The present study, however, is confined to observations on standing height and weight. The presentation of the other data is reserved for later publications. I From Field Investigations in Child Hygiene, United States PubUc Health Service, in cooperation with the Statistical Office, United States PubUc Health Service. Reprint from the Pubhc Health Re- ports, vol. 37, No. 20, May 19, 1922, pp. 1185^1207. 1 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. SCOPE OF THE STUDY. A statistical study of the height and weight records of the 14,335 children was made along the following lines: 1. A series of comparisons of the mean heights and weights at dif- ferent ages for the two sexes for the purposes (a) of discovering such differences as might exist at various ages between boys and girls with respect to height, weight, and the relation of weight to height; and (&) of observing the rates of growth in these respects during the period of 6-16 years. 2. The degree of variation in heights and weights at each age for either sex in terms of the standard deviation and the coefficient of variability. 3. The degree of correlation between the heights and weights of individuals of either sex at each age, using the correlation coefficient and ratio and regression coefficient as expressions of the relation. 4. The construction of a table of heights and weights according to single years of age for boys and for girls of the particular racial group and geographical section selected. The detailed data and certain statistical constants derived there- from are presented for reference in appended tables. GENERAL CONSIDERATIONS. Residential distribution. — The school children here considered were from various rural districts, small towns, and cities of moderate size in the four States mentioned. Their distribution according to locality is shown in Table I. Table I. — Distribution of 14,335 children observed for height and weight according to locality of residence. Name of locality. Nature of locality with approximate pop- ulation of urban localities. Number of children observed. Frederick County, Md Petersburg, Va. . . Rural, village, and Frederick, town (10,000). City (30,000) 4,348 1,748 1,153 3,822 2,562 702 Town (6,000) Charlotte, N. C City (45,000) Spartanburg, S. C City (20,000) and near-by mill villages... City (20,000) It is believed that these localities are fairly representative of the section included within the four States. As mentioned above, in order to exclude differences in race stock as far as possible, except in so far as native-born persons in this section are affected by them, the 14,335 individuals selected are of native-born white parentage. Sex and age distribution. — ^The sex and age distribution of the children are shown in Table II. HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 3 Table II. — Distribution according to sex and age of 14,335 native white children observed for weight and height in certain localities in Maryland, Virginia, North and South Carolina. Age at nearest birth- day (years). Number. Per cent. Boys. Girls. Boys. Girls. 7,132 380 745 904 8S9 973 871 781 679 471 278 161 7,203 353 735 854 900 936 847 805 695 528 331 219 100.0 5.3 10.4 12.7 12.5 13.6 12.2 11.0 9.5 6.6 3.9 2.3 100.0 4.9 10.2 11.9 12.5 13.0 11.8 11.2 9.6 7.3 4.6 3.0 6 7. 8 9. 10 11 12 13 14 15.. . 16 Tlie age at nearest birthday is employed in this study. The distribution according to age is quite similar for the two sexes, although, as was expected, a slight preponderance of girls is to be noted at the ages 14 to 16, inclusive, because of the greater tendency on the part of older boys to quit school. For both sexes the numbers observed at the ages of 6 to 14, inclu- sive, are sufficiently large to constitute reasonably fair samples of the population of this section. Less dependence can be placed on the representativeness of the data for the ages 15 and 16 because of the relatively small numbers of children comprising these age groups. This should be borne in mind when certain irregularities appear in the analysis which seem to be peculiar to the ages named. ^ I. Mean Heights and Weights. The measurements of children considered in this study were all made by medical officers of the United States Public Health Service in the schools of the various localities included. The children were measured as they were dressed, and in shoes except when the child was attending school barefooted. Weights were taken with wraps and heavy coats removed, leaving only the ordinary indoor clothing. The measurements are so classified that the mid-points of imit classes fall on the even inch and the even pound. MEAN HEIGHTS AND WEIGHTS OF BOYS AND GIRLS AT DIFFERENT AGES. The basis for the first series of comparisons is given in the table of mean (arithmetic average) heights and weights ^ (Table III) . 2 The probable errors of the mean heights and weights at each age are given in appendix. Table XXI. ^ The mean rather than the median or modal heights and weights have been used for the reason that the means appear to be satisfactory expressions. The modes are difficult to define in some instances because of somewhat irregular distributions due to small numbers. The medians are in all instances somewhat lower than the means, but their variations are similar in all essential respects to those of the means. (See appendix, Table XXl.) Furthermore, the means are more useful in comparing our results with those of other studies, and are more desirable in expressing degrees of dispersion and correlation. 4 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. Table III. — Mean heights and weights of 14,SS5 native white children in Maryland, Virginia, North ana South Carolina, at each age, compared for boys andgirls.^ Age at nearest birth- day (years). Height (inches). Weight (pounds). Boys. Girls. Boys. Girls. 6 45.4 46.8 48.8 50.7 52.6 54.3 56.2 58.0 60.3 62.9 64.6 44.8 46.6 48.5 50.5 52.5 54.5 57.0 59.3 61.1 62.5 63.3 47.5 50.4 54.5 59.6 65.2 71.1 78.0 85.1 95.4 108.4 116.7 45.5 48.3 52.4 58.0 64.0 70.3 79.7 89.7 99.4 107.6 113.6 7 8 9... . 10 11. 12 13 14 15 16 1 Probable errors of the means are shown in appendix, Table XXI. The differences between the means for boys and girls at a given age period are not great, but they are significant. Table IV, showing the differences, will assist in making the comparison from this point of view : Table IV.- -Comparison of the mean heights and weights {as given in Table III), showing the excess in favor of either sex at different ages. Age at nearest birth- day (years). Excess in the mean- Height of— Weight of— Boys over girls (inches). Girls over boys (inches). Boys over girls (pounds). Girls over boys (pounds). 6 0.6 .2 .3 .2 .1 2.0 2.1 2.1 1.6 1.2 .8 7 8 9 10 11 0.2 .8 1.3 .8 12 1.7 4.6 4.0 13 14 15 .4 1.3 .8 3.1 16 It will be noted in the group studied that on the average at the ages of 11 to 14, school girls are taller than school boys, and that at the ages of 12 to 14 the girls are also heavier. This observa- tion merely corroborates for the particular racial and geographic group under consideration what has been found by other observers to be uniformly true during the period of puberty. WEIGHT-HEIGHT INDEX. The relation of weight to height, commonly expressed in the form of the ratio of weight to height at each age and called the weight- height index, is shown in Table V. HEIGHTS AND WEIGHTS OF SCHOOL CHILDEEF. Table V. — Weight-height indices, or the ratios of mean weight to mean height, at each age for 14,SS5 native white children in Maryland, Virginia, North and South Carolina, compared for boys and girls. Age at nearest birth- day (years). Mean weight in pounds Mean height in inches Boys. Girls. 6 1.05 1.08 1.12 1.18 1.24 1.31 1.39 1.47 1.58 1.72 1.81 1.02 1.04 1.08 1.15 1.22 1.29 1.40 1.51 1.63 1.72 1.79 7 8 9 10 11 12 13 14 15 16 The differences in the indices for the sexes, it will be noted, occur at the same ages, approximately, as the differences in weights and heights considered separately. Computed from Table V, they are given for convenience in Table VI. Table VI.- -Comparison of the mean weight-height index (as given in Table V) showing the excess in favor of either sex at different ages. Age at nearest birthday (years.) Excess in the mean weight-height in- dex (pounds per inch of height). Boys over girls. Girls over boys. 6 0.03 .04 .04 .03 .02 .02 7 8 9 10 11 12 0.01 .04 .05 13 14 15 16 .02 Here, again, it is found that the results correspond in a general way to those of similar studies of other groups of children. The boys are heavier than the girls for each inch of height at the ages of 6 to 11, both inclusive, and at 16. At the ages 12 to 14 the girls weigh more than the boys, and at 15 no difference appears for this group of children. RATE OF INCREASE IN HEIGHT AND WEIGHT. The series of means given in Tables III and V suggest an interpre- tation from the point of view of development ; and considered in this light, although constituting observations of different individuals 6 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. at each age, they approximate the records of growth of the same individuals. The rate of increase in height and weight or in the weight-height index is not easily seen from the tables of means and ratios. Per- RATE OF INCREASE IN HEIGHT AND WEIGHT NATIVE WHITE. CHILDREN fe-|t, YEARS OF AGE IN MARYLAND VIRGINIA, NOKTH AND SOUTH CAEOLINA At^e. -a-t Ne.o.re.st Birthdei.>^ 6 7 8 S 10 II 12. 13 14 IS l(> 70 ■ I 1 1 1 1 1 1 1 ' 1 ■ - ■ 1 ■ i 1 l MEAN HEIGHTS ^^rf**"^^^ it,o — - 1^^ ''^ i/i Q _ . _ ^ *" .^"^"^ DO^S ^^^^_^„,-'^ &i Q,\r\^ ^^^ Of 5S- ^^^^•"""^ • xf .^.^ ^ 'iso- ^.-tf****^ - 0- ^— -"tf^"^ -''VS. 1 1 1 1 1 -H 1 1 1— 1 1 1 1 \ 1 1 1 1 1- f- 1 1 no ■ '/ ' lOO MEAN WEIGHTS ^'V so Bo>,s // Girls /y • 80- ,'^ • to ^o - jy . Ul ■" jy^ J- ^^> at VV' j°-^ c-^ ^r • -Cfeo *j ^ f I o- ^^ * Q / •' 1 _J So- « ^^^ ^^ « ^^ ^A -<»•■ — ^%J~ fc 7 8 <3 10 II IZ IS 14 15 lb A<^e. o-t. Nearest BirlVidav. - haps the quickest and simplest way to show it is to .plot them on a logarithmic vertical scale. The means in Table III have been plotted in Figure 1.* ^ In constructing the vertical scales for height and weight the spacing has been so arranged as to allow approximately the same space for an inch of height as for a pound in weight. The horizontal scales correspond exactly. The slope of the four Unes, therefore, is comparable. HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 7 The curves also illustrate graphically the comparison of the actual mean heights and weights of boys and girls at different ages. If the mean heights or weights fall in an absolutely straight line on a logarithmic scale (the scale being so constructed as to give the same results had the logarithms of the means been plotted on ordinary cross-section paper), obviously the rate of increase is unchanging. There are, however, quite definite curves in the lines connecting the points, indicating as other investigators have pointed out, that the rate of increase in either height or weight varies at different ages for both boys and girls. The rate of increase in the height of boys shows a tendency to slacken between the ages of 11 and 13; and the same slackening is seen for girls, but not until the age of 13. The mean weights of boys show an accelerating rate of increase imtil the age of 15, with a marked impetus at the age of 18. For girls the weight curve rises more rapidly than for boys up to the age of 13, where the slackened rate of increase begins and continues through the last year of age (16) for which data are avail- able. These variations in the rate of increase are expressed numerically in Table VII. Table VII. — Percentages of annual increase in mean height and mean iveiglit of 14,335 native white children in Maryland, Virginia, North and South Carolina, compared for boys and girls. Age period. Percentage increase in— Height. Weight. Boys. Girls. Boys. Girls. 6to7i 4.0 3.9 3.9 3.8 3.1 3.4 3.4 4.0 4.7 3.0 4.1 3.9 4.4 3.8 3.9 5.2 4.2 2.9 . 2.0 1.5 6.1 8.1 9.4 9.4 9.0 9.7 9.1 12.1 13.6 7.7 6.2 8.5 10.7 10.3 9.8 13.4 12.5 10.8 8.2 5.6 7 to 8 8 to 9 9 to 10 10 toll 11 to 12 12 to 13 13 to 14 14tol5 15 to 16 ' All ages are those at nearest birthday. The relatively faster increase in weight than in height suggests, of course, that the weight-height index increases as children grow older. The curves constructed by plotting the weight-height in- dices in Table V on a logarithmic scale are shown in Figure 2. Beginning at about 8 years of age the rate of increase in the weight- height index is markedly slower for boys than for girls up to the age of 13 or 14. Thereafter the opposite is true. The means given in Table V may be used in still another way in considering the question of growth in weight in relation to height. 8 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. If the annual increment in weight be divided by the annual incre- ment in height for the corresponding year of age, we will obtain a series of figures showing the annual increase in weight per each inch of increase in height. Table VIII presents the annual increments computed from the means given in Table III and the ratios found in the manner suggested. RATE OF INCREASE IN THE WEIGHT-HEIGHT INDEX NATIVE WHITE CHILDBEN 4 TO Ifc YEARS OF AG£ IN MARYLAND, VIKGINIA, NOR.TH AND SOUTH CAROLINA •-^ 1.8- ji ^^^^ tr y5 Q) ^■'^'^ «£■; i.fo- Girls — — — »• ^-^//^ -Otx- ^ ^^ i Ol'> ^^^^ X a ^^^^ +'0-r ^^^^^ -^i '•4- e^^ «)<... ^^^^ XU 1. k ^^^^ ^^s- ^^,^^' -5-1 -> »-2-- _^>^''^^'' 'l^ ^^^'^^^ ^t ^^^^^t*!^"^,^^ \-> II 6 7 8 1 10 II a IS 14 IS Ife Acje at Nearest Birthday Fig. 2. Table VIII. — Annual increments in •pounds oj weight J or each inch oj inarement in height computed Jrom mean weights and heights oj 14,335 native white children in Mary-, land, Virginia, North Carolina, and South Carolina, compared Jor boys and girls. Age period. Annual increment. Annual in w increment eight For boys. For girls. (pounds) for each inch of increment in height. In height (inches). In weight (pounds) In height (inches). In weight (pounds). Boys. Girls. 6to7i 1.4 2.0 1.9 1.9 1.7 1.9 1.8 2.3 2.6 1.7 2.9 4.1 5.1 5.6 5.9 6.9 7.1 10.3 13.0 8.3 1.8 1.9 2.0 2.0 2.0 2.5 2.3 1.8 1.4 .8 2.8 4.1 5.6 6.0 6.3 9.4 10.0 9.7 8.2 6.0 2.1 2.1 2.7 2.9 3.5 3.6 3.9 4.5 5.0 4.9 1.6 2.2 2.8 3.0 3.2 3.8 4.3 5.4 5.9 7.5 7to8 8 to 9 9tol0 10 to 11 11 to 12 12tol3 13 to 14 14tol5 15 to 16 ' All ages are those at nearest birthday. The ratios in the two last columns, when considered as two series, merely indicate in another way the differences in the direction of growth of boys and girls. They have been plotted on a logarithmic scale in Figure 3. HEIGHTS AND WEIGHTS OF SCHOOL, CHILDREN. The gain in weight by girls for each inch of gain in height increases at an almost constant rate from 7 to 16 years. Allowing for certain irregularities in the data, the gain in weight by boys for each inch of gain in height is practically the same as that by girls up to the age of 1 1 , and thereafter is at a considerably slower rate. COMPARISON OF MEASUREMENTS OF INDIVIDUALS OF DIFFERENT AGES WITH PERIODIC MEASUREMENTS OF A SINGLE GROUP OF INDIVIDUALS. A number of observers have objected to height and weight stand- ards based on measurements of children taken in cross section, at R.ATE OF INCREASE /N THE ANNUAL INCREMENT IN NWEICHT P£R. INCH OF INCEEMENT IN HEIGHT NATIVE. WHITE. CHIUDEEN fc To 14. YEAR.S OP AGE IN M/MexUAND, VlBSINIA, NORTH AND South caroi-ina Fig. 3. different age periods, on the ground that such measurements do not furnish an accurate index of the rate of growth. It has been sug- gested that such an index can be determined with appreciable accuracy only by making periodic measurements of the same children over a number of years. On the other hand, an index determined by periodic measurements requires time, while the need for fairly reliable standards by which to gauge the state of nutrition is pressingly present. Furthermore, such a group of children, of necessity, will be a selected group which finally, through process of elimination, is likely to be composed of a relatively small number of the surviving fittest who are benefited by special contact with health educational methods. There is the danger, therefore, that the end results will not be applicable for comparison with children not subjected to special influences, and with children of other sections of the country. 10 HEIGHTS AND WEIGHTS OF SCHOOL CJHILDREN. Although the measurements made by the United States PubHc Health Service constitute observations of different groups of indi- viduals at each age, they may be compared with successive obser- vations of a single group of individuals. Using the records recently published by Prof. B. T. Baldwin, the following comparison is afforded.'^ Table VIII-A. — Mean heights, mean weights, and mean iveight-height indices of children of different ages measured by the United States Public Health Service, compared vnth corresponding measurements made periodically on a single group of children by Dr. B. T. Baldwin. Height (inches). Weight (pounds). Weight-height index (pounds). A.ee at nearest birthday. Boys. Girls. Boys. Girls. Boys. Girls. U. S. P.H.S. Bald- win. U. S. P.H.S. Bald- win. U. S. P.H.S. Bald- win. U. S. P.H.S. Bald- win. U. S. P.H.S. Bald- win. U. S. P.H.S. Bald- win. 6 45.4 46.8 48.8 50.7 52.6 54.3 56.2 58.0 60.3 62.9 64.6 45.4 47.8 49.8 51.5 53.5 55.3 56.9 59.3 61.8 64.1 66.7 44.8 46.6 48.5 50.5 52.5 54.5 57.0 59.3 61.1 62.5 63.3 44.3 46. S 49.1 51.1 •53.1 55.3 57.6 60.1 61.8 62.7 63.6 47.5 50.4 54.5 59.6 65.2 71.1 78.0 85.1 95.4 108.4 116.7 45.2 50.6 55.3 60.7 67.2 73.1 77.7 88.4 98.3 109.4 120.6 45.5 48. 3 62.4 58.0 64.0 70.3 79.7 89.7 99.4 107.6 113.6 42.6 48.0 53.8 59.7 67.2 74.1 83.9 96.2 107.2 115.5 120.6 1.05 1.08 1.12 1.18 1.24 1.31 1.39 1.47 1.58 1.72 1.81 0.99 1.05 1.11 1.17 1.25 1.32 1.36 1.49 1.59 1.70 1.80 1.02 1.04 1.08 1.15 1.22 1.29 1.40 1.51 1.63 1.72 1.79 0.96 7. 1.02 8 1.09 9 1.16 10 1.26 11 1.33 12 1.45 13 1.60 14 1.73 15 1.84 16 1.89 In the case of the boys, the height and weight curves follow the same general trend, with Baldwin's group slightly above that of the Public Health Service at practically every age. The weight-height indices for the two groups of boys are practically the same at each age except 6 years. In the case of the girls, the heights of the two groups foUow much the same course, with a shght convergence of the curves at the older ages. The weight and the weight-height index curves for the girls show a tendency to diverge after 7 years of age, and the divergence is considerable by the age of 16. Some factor evidently influenced the growth of the girls measured periodi- cally which failed to influence the girls measured by the United States Pubhc Health Service. Otherwise the curves appear to be as similar as could be expected. n. Difference in Heights and Weights of Children of the Same Sex and Age. Thus far comparisons in this study have been made of average (mean) heights and weights, but at each age children differ con- siderably in these respects and the differences are greater at some ages than at others. The averages which have been studied do not take into accoimt these differences because the average (arithmetic 6 Physical Growth of Children from Birth to Maturity. By Bird T. Baldwin, University of Iowa Studies in Child Welfare, 1921. Baldwin's figures are based on semiannual measurements of an average of 125 boys and 125 girls from the Horace Mann School, Teachers' College, Columbia University, New York, for periods of 8 years or more. (P. 411.) HEIGHTS AND WEIGHTS OF SCHOOL CHILDBBN. 11 mean) does not show for any group of children the range of weights or heights, or the "dispersion" of weights or heights above and below the average. The nature of these differences is shown by plotting the number of children at each height or weight. As in all biometrical distri- butions of this character, the distribution will be found to form a RATE of increase in weight, in height, and IWTHE weight- height INPEX OF CHILDREN OF DITTERENT AGES MEASURED BY THE U.S. PUBLIC HEALTH SER.VICE COMPARED WITH CORRESPONPING PERIODIC MEASUREMENTS OTA SINGLE GROUP OT CHILDREN BY B.T. BALPWIH Fig. 3a. more or less symmetrical frequency curve, which means that most of the children will tend to fall within rather narrow height or weight limits and fewer and fewer will fall in the classes toward either extreme. In plotting Figure 4, the percentages at each height or weight interval are used so as to reduce the data for the different ages to the same basis vertically. 12 HEIGHTS AND WEIGHTS OF SCHOOL CHILDEEN. VARIATION IN HEIGHT AND IN WEIGHT PEECENTAGE DISTEI BUriONS ACCOEDINC TO HEIGHT AND ACCOKplNC TO WEIGHT OF NATIVE WHITE CHILDREN OF PlFFERENT AGES I N MARYLANP, V I ESI N 1 A , NORTH ANP SOOTH CAROLINA HEIGHT Z-INCH CLASSES WEIGHT S-POUNP CLASSES ''sjiij-jsjiiiiij; I HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 13 The differences in the sha'pe of the curves for heights as well as for weights are quite marked when ages are compared. In general, the older the age, the flatter is the curve and hence the greater the dispersion. This means that children of a given age differ more widely in height or weight as they grow older. This statement should be quahfied, however, for a closer study of the graphs affords the suggestion that the greatest dispersion or difference occurs at the age of puberty. Differences of this character are exhibited by both boys and girls. STANDARD DEVIATION IN HEIGHTS AND WEIGHTS. A more nearly exact expression of these differences than that afforded by the graphic method is necessary. The usual statistical term used to express the degree of differences in distribution is the standard deviation (o-), which, in turn, is expressed by (F) the coefficient of variability as a percentage of the mean. As the a- or the V is large or small, so the differences in the individual heights or weights are large or small. In Table IX are given the standard deviations in heights and weights at each age for boys and girls and the corresponding coeffi- cients of variability. Table IX. — Variation in heights and weights oj hoys and girls oj the same age. As expressed in standard deviations in standing heights and weights at each age of 14,335 native white children in Maryland, Virginia, North and South CaroUna, and the corresponding coefficients of variabiUty. Age at nearest birthday. Standard deviation. Coefficient of variabiUty. Boys. Girls. Boys. Girls. 6 STANDING m EIGHTS. 2. 77 ±0.068 2.5S± .045 2.54± .040 2.66± .043 2.64± .040 2.82± .046 3.03± .052 2.93± .054 3.83± .084 3.85± .110 2.99± .112 3. 21 ±0.081 2.53± .044 2.47± .040 2.69± .043 2.83± .044 3.00± .049 3.02± .051 3.16± .057 2.99± .062 2.62± .069 2.50± .081 6.10 5.51 5.20 5.25 5.02 5.19 5.39 5.05 6.35 6.12 4.63 7.17 5.43 5.09 5.33 5.39 5.50 5.30 5.33 4.89 4.19 3.95 7 8 9 10 11 12 is 14 15 16 6 VTEIGHTS. 7.76±0.190 6.56± .115 7.13± .113 7.98± .128 9.09± .139 10.30± .166 12.43± .212 12.84± .235 17.52± .385 20.46± .585 17.12± .644 7. 27 ±0.185 6.26± .110 7.39± .121 9.24± .147 10.79± .168 12.87± .211 14.85± .250 16.41± .297 14.75± .306 16.38± .429 16.244- ..523 16.34 13.02 13.08 13.39 13.94 14.49 15.94 15.09 18.36 18.87 14.67 15.98 12.96 14.10 15.93 16.86 18. 31 18.63 18.29 14.84 15.22 14.26 7 8 9 10 11 12 13 14 15 16 14 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN, The coefficient of variability is, of course, the best expression of the degree of variation, since it takes into account the size of the mean from which the deviations are measured. As the table and the graph (Fig. 6) clearly show, there are marked differences in this coefficient for weight at different ages for the same sex and, when the sexes are compared, for the same age. After the age of 7 the variation of weight increases with age up to 13 years for girls and 15 years for boys, and then decreases, the decrease thus beginning at an earlier age for girls than for boys. Comparison of the Annuau Increment in Weight With the Standard Deviation in Weight At DirFEBENT A<3ES For. Boys and Girls 8 «1 10 II 1Z 13 Fig. 5. RATE OF GROWTH AND VARIATION IN WEIGHT. It is of interest to inquire the reasons for the greater variation in weight at certain ages. While it might be due in part to a greater percentage of abnormal children at certain ages who may vary more from the mean than the normal children, the rapidity of growth as expressed by the mean annual increment in weight is definitely associated with variation in weight, as shown in Figure 5. HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 15 A comparison of the mean annual increment (see Table VIII) with the standard deviation (see Table IX) for the same sex shows this correlation in a more striking manner. The variation in weight seems to increase or decrease with the mean annual increment. That is to say, children vary most in weight at the periods of the most rapid increase in weight. These differences from the point of view of sex are also striking. Tlie degree of variation in weight for boys and girls of the same age Variations in the Standing Heights aho Weights of Boys amo GiRus AT DirreeENT Ages in Terms of Coetficient of Variability Based on observations of ia,33S School Children «n Marv lind, Virqint'a. J North iMid Sou.lh Carolina, by U. S . Pixb I ic Health Service. T 1 1 1 1 1 1 I 20 -• 18 ■■ Ife .. ^_^ 14- + N^ \Z ■- 10 -- 8 • 6 - 4 ■- Weights Boys Standing Heights Bo>(s Girls 7 8 9 10 n li 13 Ape at Nearest BirthdaY Fig. 6. is by no means the same as the standard deviations (see Table IX and Figure 5, upper curves) clearly indicate. The same sort of differences between the sexes is shown when the annual increment in pounds is compared. (See Table VIII and Figure 5, lower curves.) RELATION OF HEIGHT TO VARIATIONS IN WEIGHT. In comparing the degree of variation in weights for boys and girls the factor of height must also be considered. The degree of variation 109764°— 22 2 16 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. as expressed by the coefficient of variability is plotted for weights and heights for either sex in Figure 6. Since the two sets of curves are quite different in some respects, an attempt has been made to see what the coefficients of variability in weight would be if no variation in heights had existed. This has been done by a method of averaging the coefficients of variability in weight for children of a given age at each inch of height, a method which is admittedly somewhat crude but accurate enough for the purpose in view." Table X. — Variation in weights of boys and girls of the same age, after eliminating (roughly) the effect of variation in height. As expressed by the weighted averages of the coeflacients of variability for weight at each inch of height. Age at nearest birth- day. Averages of the coeflficients of variabiUty. Boys. Girls. 6 8.48 9.06 8.99 8.65 9.49 9.95 10.28 10.40 10.51 9.66 9.04 8.55 8.39 8.73 10.74 11. 25 12. 01 12.15 12.60 13.30 12.68 11.50 7 8 9 10 11 12 13 14 15 16 The results given in Table X are shown graphically in Figure 7. It appears that girls over 8 years of age vary with respect to weight in a considerably greater degree than boys of the same age and of the same approximate height. The degree of variation is somewhat more pronounced after the age of 13. III. Correlation of Height and Weight. Thus far the children of given age and sex have been considered from two standpoints: First, as constituting groups, using the average (mean) heights and weights of different sex-age groups for making comparisons; and, second, as individuals, using the standard deviation and coefficient of variability as measures of variation for determining the degree individual children differ in respect of height and weight. It now remains to consider the differences occurring in individual children in each group from the point of view of the relation of variation in height to variation in weight. That is, how closely do variations in height correspond to variations in weight among children of different ages and sexes ? Obviously, if there is a very close relationship, there must be a marked uniformity in the 6 See appendix, Tables XV and XVI, for the coefficients of variability at each height. The coefficients of variabihty in weight of children of a given age increase Uttle, if any, withincrease in height. It therefore seemed feasible to average these coefficients for a given age group in order to get an expression of the average relative variation in weight of children of any given height for that age. HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 17 weight of children, taking height into account; if there is not a very marked relationship, children of a given height, age, and sex will differ widely in weight. The importance of this phase of the discus- sion does not lie so much in demonstrating the fact that a relation- ship of this kind exists, since in the very nature of things it must exist, as in discovering the differences in degree of correlation for the various sex and age groups. COEFFICIENT OF CORRELATION. A comparison of this kind would be a very detailed and difficult task if no single measure of the relationship between the degree of Variation in Weights of Boysanp Cukls of the Same Ace, AFTee Eliminating THE Etfect of Variation in Heioht WElCHTEP AVEEACeS OF CoE Fl^iciE NTS Op VAEiA Bi 1-1 T Y To R. VMEienT AT EACH INCH OF HEIGHT 14 -• iT Ac^a a-l: Neo-rest. Birlhda^ Fig. 7. the two variations could be used. Such a statistical measure exists in the coefficient of correlation and the correlation ratio. When this coefficient or ratio is zero there is no relationship whatsoever. When it is 1, or unity, the relationship is perfect; that is, the variation in one (e. g., height) is accompanied by exactly the same variation, relatively, in the other (e. g., weight). The nearer unity, the closer the relationship between the two variables.^ 7 The coefficient of correlation (r) is the generally used statistical measure of linear or straight Une correla- tion between two variables. If the items (individuals) are plotted with heights as ordinates and weights as abscissae, and the points (or the means of the weights at the different heights) tend to fall along a straight Une, the correlation is said to be hnear. But if the points tend to fall along a curved Une, the correlation is said to be nonUnear and, under certain conditions, the correlation ratio (?;) is a better measure of the correlation between the two variables. If the ratio (?;) is significantly larger than the coefficient (r), it is an indication of noiiUuearity. In the case of the heights and weights of children in this study, the differences between the correlation ratio and the coefficient are not marked except at a few ages, but in practicaUy every instance they are found to be significant if Blakeman's criterion of nonlinearity is appUed. That is, the correlation ratio is a more nearly accurate expression of correlation than the coefficient for the material used iu this study. 18 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN, The correlation ratios as well as the coefficients of correlation for heights and weights of boys and girls at each age are given in Table XI, together with their probable errors. The correlation tables are given in the appendix. Table XI. — Correlation of standing heights and weights of native white children in Mary- land, Virginia. North and South Carolina. Age at nearest birth- day. Correlation ratio of weight on height CoeflBcient of correlation (r). 6 BOYS. 0.8-30±0.010S .704± .0125 .718± .0109 .744± .0101 .720± .0104 .726± .0108 .736± .0111 .720± .0125 .816± .0104 .8.53± .0110 .784± .0225 0.782±0. 01.34 .603± .0157 .682± .0120 .643± .0133 .693± .0113 .657± .0130 .706± .0121 .e87± .0137 .795± .0114 .842± .0118 .736± .0244 7 8. . . . 9 10 11 12 13... 14 15 16 6 GIRLS. 0. 788±0. 0136 .725± .0118 .751± .0101 .724± .0107 .709± .0110 .695± .0120 .719± .0115 .707± .0128 .692± .0153 .543± .0262 .592± .0296 0.675 ±0.0195 .679± .0134 .719± .0111 .661± .0127 .660± .0125 .647± .0135 .703± .0120 .669± .0141 .643± .0172 .427± .0303 .565± .0310 7. . 8 9 10 11 12 13 14 15 16 As may be expected, in all instances the correlation is high and, from the point of view of the probable error, significant. The degree of correlation, however, varies considerably in the different ages and as between boys and girls. These differences are not merely acci- dental, but indicate definite trends. In order to visualize the differ- ences the correlation ratios have been plotted in Figure 8. The correlation of height and weight is quite high at 6 years of age for both boys and girls in this particular group of children. From 7 to 13 years of age the correlation for both sexes is lower and similar, although that for the girls is slightly lower after 8 years than for boys. After the age of 13 there is a marked divergence, the correla- tion for boys being quite high and that for girls relatively low. Stated in other words, the weights of both boys and girls vary in pretty much the same way as do the heights in the ages under the age of 14, the taller the children the more they weigh according to a fairly constant ratio; but in the ages 14 to 16, height or weight appear to be affected to a markedly greater extent by some other factor or factors. HEIGHTS AND WEIGHTS OF SCHOOL CHILDEBN. 19 VARIATION IN WEIGHT PER INCH OF VARIATION IN HEIGHT. This may be expressed more exactly by stating the variation in weight (pounds) per inch of variation in height at each age, as shown in Table XII, and graphically in Figure 9.^ Table XII. — Variation in weight (pounds) per inch of variation in height compared for boys and girls at different ages. CoeflBcieiit of regression of weiitht on height of native white children of Maryland, Virginia, North and South Carolina by sex and age. Age at nearest birth- day. Coefficient of regres- sion of weight on height (pounds). Boys. Girls. 6 2.19 1.53 1.91 1.92 2.38 2.41 2.91 3.02 3.66 4.46 4.24 1.52 1.68 2.15 2.27 2.52 2.79 3.44 3.48 3.16 2.69 3.70 7 8 9 10 11 12 13 14 15 16 From 7 to 13 years, inclusive, the variation in weight per inch of variation in height was less among boys than girls; at 6, 14, 15, and 16 years of age the opposite was true. IV. Summary. 1. The basis of this study consists of height and weight measure- ments of 14,335 native white school children from 6 to 16 years of age made by officers of the United States Public Health Service in representative localities of Maryland, Virginia, and North and South Carolina. 2. The mean heights of the girls 11 to 14 years of age, inclusive, and the mean weights of the girls 12 to 14 years, inclusive, are greater than those of the boys of the same ages. At the other ages studied the boys are taller and heavier than the girls. The weight- height index (weight per inch of height) of the girls exceeds that of the boys from 12 to 14 years and is equal at 15 years; at the other ages studied, it is greater for boys than for girls. 3. The annual increment in weight of the girls exceeds that of the boys from 8 to 13 years, inclusive. At the other ages studied it is greater for boys. However, when the annual increment in weight 8 The coefficient of regression of weight on height (computed from the coefficient of correlation (r) for a given age indicates the average difference in weight (pounds) per inch of difference in height. 20 HEIGHTS AND WEIGHTS OF SCHOOL. CHILDREN. per inch of increment in height is considered, it is found greater for girls than boys at every age after 6, except 10 years. 4. Variations in height and in weight differ markedly for different sex-age groups and are closely associated with the rate of increase in weight. When variation in weight is considered independently of variation in height, the boys 14" to 16 years of age vary considerably more in weight than the girls of the same age. But when the effect of variation in height is eliminated, the girls vary more in weight than the boys of the same age at all ages above 8 years. In other Correlation Ratio (yj) Between Heights and Weights MATIVE WHITE CHILOREN 6 - Ifc YEARS OFAOE JN W AE Y I- A NP^ VlKGIN)A j NoeTH AND Sooth CaKoi-ina ■M kO '"-^^^ Boys — ^ Girls 4S-. -^oT^ Ac^e. -zj-t Nearesi Blrthda-y Fig. 8. words, girls after 8. years of age vary more in weight than boys of the same age and height. 5. Correlation between heights and weights was found to be lower j for the girls than for the boys at all ages above 8 years and markedly j lower after 13 years of age. V. Height-Weight Tables. Since it appears that variability in weight differs with sex, age, and f height, it seems that averages which best represent a group of chil- dren are those which take all of these factors into account. It there- HEIGHTS AND WEIGHTS OF SCHOOL (CHILDREN. 21 fore seemed best to present the final results of the study as average weights of boys and girls of each age, by height groups. A series of mean weights was therefore computed independently for children at each year of age and at each inch of height. In order to approximate the true average weights which would be the result of measuring an infinite number of children, it was necessary to smooth the weights computed independently. Smoothed averages were derived from data shown in the tables^ in the appendix, by a formula from the Average Variation in Weight (pounds) roe. a Vaciation of One Inch in Height As ExPRBssEO By The coeFFiciENr OF' "EeGE.essiop( oP wGioMT ON HG(CHT OPN/^flVE WHirS CHll-DaEN OF MARVL«NO,vreoiNlA, Naertl AND SOUTH CAH.01-1IMA 3.0- S-- 8 <) lO II \Z Fig. 9. method of least squares, which give a series of weights representing the most probable smooth curve which could be constructed from the data.^*^ The smoothed averages are shown in Tables XIII and XIV. 9 The actual average weights, the standard deviations, and the coefiBcients of variability are given by single-year age groups and single inch-height classes in appendix Tables XV and XVI. The number of children whose measurements were considered in making up each average is also shown. 10 Let y= weight and X= height; then it was assumed that at any given height, X", Y=a+bx+cx^+dx^. The coefficients a,b,c, and d were evaluated by the method of least squares for each sex and age, and the smoothed weights were computed by substituting in the original equation. 22 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. Table XIII. — Smoothed average weights for each inch of height of native rvhite school- hoys in Maryland, Virginia, and North and South Carolina, ages 6 to 16 years, inclusive, for each year of age. Height, nearest inch. Weight, nearest pound at each age, nearest birthday. 6 years. 7 years. 8 years. 9 years. 10 years. 11 years. 12 years. 13 years. 14 years. 15 years. 16 years. 41 42 43 44 45 46 47 48 49 50 39 41 43 44 46 48 50 52 54 43 44 46 48 50 52 54 56 59 47 48 49 50 52 54 56 59 61 64 67 50 51 53 55 57 60 62 65 68 72 74 50 52 54 56 58 61 64 66 69 72 74 77 80 55 57 59 61 64 67 70 73 76 79 82 84 86 65 67 69 71 74 76 80 83 86 89 92 67 69 72 75 78 81 85 88 91 95 99 103 107 75 77 80 83 86 90 93 97 102 106 111 116 121 90 95 100 104 109 113 118 124 1.30 104 109 114 118 124 130 136 51 52 53 64 55 66 67 58 69 60 61 62 63 64 65 66 67 68 Table XIV. — Smoothed average weights for each inch of height of native white school- girls in Maryland, Virginia, and North and South Carolina, ages 6 to 16 years, inclu- sive, for each year of age. Height, nearest inch. Weight, nearest pound at each age, nearest birthday. 6 years. 7 years. 8 years. 9 years. 10 years. 11 years. 12 years. 13 years. 14 years. 15 years. 16 years. 39 40 41 42 43 44 45 46 47 48 49 50 38 39 40 41 42 43 45 47 49 51 53 47 49 52 54 56 59 61 64 67 71 73 52 55 58 60 63 65 68 71 74 77 81 86 90 62 64 66 69 72 75 79 83 87 90 94 98 101 69 70 73 76 79 83 88 92 96 100 104 108 110 81 84 87 91 95 99 103 107 110 114 116 89 92 95 99 102 105 108 112 115 119 122 103 106 109 112 115 119 126 42 42 43 45 47 49 51 53 55 57 68 42 43 45 47 49 51 54 56 58 60 61 47 49 52 55 67 60 62 65 68 71 73 76 79 51 62 53 64 65 66 57 58 59 60 61 62 63 64 65 66 1 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 23 No attempt was made to cany the smoothed mean weight series to the extreme limits of heights. In the first place reliable averages could not be computed because of the relatively small number of children observed. In the second place averages would probably not be good criteria of the correct weights of extremely short or extremely tall children, inasmuch as those who vary so widely in height from the mean could not be assumed to conform to any computed or assumed mean weights. It is not claimed, however, that this table reaches the limits of normality, especially in the older ages; but it appeared better to keep within safe limits where the data could be relied upon than to try to make a complete table if it were necessary to use unreliable figures for the extremes. It is suggested that this table, which is based on measurements of native white children in four representative Southern States, might serve as a table of correct weights among such children of the South. The usual tables of this sort are based on measurements of children of various racial stocks or distinctly selected groups of children, and it would seem that a table, based on measurements of children of a single race stock from one section of the country, would better represent the white children of that section. It should be borne in mind, however, that the older ages, particularly the 16-year-old boys, probably are not representative, because of the small number considered and selection due to children dropping out of school. VI. Appendix. TABLES OF BASIC DATA. In the following pages are given tables containing the basic data for the study. Tables XV and XVI show by sex, age, and height the mean weights, standard deviations, and coefficients of varia- bility. These tables contain the basic data from which Tables XIII and XIV were computed. Tables XVII to XX, inclusive, show by sex and age the percentage distribution of children according to height by 1-inch classes, and according to weight by 5-pound classes. Table XXI shows the mean heights and weights with their probable errors and the median and quartile heights and weights by sex and age. Tables XXII to XXXII, inclusive, show the original data in correlation tables. 24 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. I •I 1 1* r« O *4i o o 51-' 0) « (3 ^mScmS cocococcm eocococoeo ^ -^ -^ CO -^ K3 vD t^ 00 a> •*■* ■*'!<■*■>»<■* -■BjjBA JO :)n3T0ig9O0 10 CD •spmiod -'noi:jBiA8p pjepoB^g 05 1^ 5>co 06 CO •spnnod '^q3i8M nean n>. . . 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'CO -<: ■ lO O^OCOt^iM OOlt^CD^ |CO moo-*-*-* rf>OiOio •naipiiqo jo jaqnmjvj gi • : :-' : : ; i^'- • (M oOt-hcooOt-4 i-iTj^oot^cq 1 i-Hr-Hco oooqcMoo 03 to !>> CD -BUBA jo ^naioggeoo i i i^J 1 1 lost ■-^ooo coo6i>t>^oj •spnnod 'noi:jBiAap pjBpnBjg : I :SS II lc<3c HCOCO IO-^tHCDOO '^^lO lr-O5t^00iO OCOM* cocococo^o •spnnod '^qSiaM. treaH ■O O -* IN T-^ r-( r^cDQOcOOS • CD oo050co>o »or-^oi(Nio •naipijqo jo jaqnmjvi S ; CO 1 • 'CO »Ot^cDCOO »OOQ0O»0 ; . %H(NCOCO COcOCOCOrH 1 f S ; ■s : ^ : ss gss • cooi Srs' i^^ ^ CD t> -oc 1 •* i HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 25 1^00 o»Q- O Oi O 05 "■ 5Q t~- 1^ 0> OS oi'-tco'^oo r*o>»oooN r^F-^»Q<:dd ?^7fgJC2?5 t:r^P^i^;2 t-C eO oi ^ ^ 00 0> I'- <"" ^ to i:0 cO CO O CD CD t- t^- l>- I 26 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. '::^ •g ^ ■"^ rSS O J3 Is CO O ©IS 1^ MO" s. 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COClOiM r^iooooo t^o 5»oicuo ododcic4 1^ ^S co»oo osod t^ C4^^ t^ t^ ^ CO t^ o t^ -- (M CO O ■*»< COCOiCOlCO C4 lO ^ oo o ^-^COC^ (N-M o o r- a> -^ -^ CO 00 CO O -^ - -.---._ '^O'^COCO 00 1-H 00 r^ »o I-- to CO .— I CO CO irfO--* OiOOOOS oos-H*o6c5 OiiCiC COCO.-hCo>^t^ 00-^ — o^ c^oOr^cococp x'»ocp ■OcOcDCOt^ t~-r-b»XX XOiOOO -— <^hOs coo— "C^ Oi C^'^OX O — X h- t X-Mt^r*-^ COCOOCD"* '^TJ^r Ji-HNCO-^ iOOI-*XOs 0-^C^CCtJ4 i-OcOt^OOOl 0'-<(M 5 lO »0 iO to lO lO lO >0 lO CO O CO CO O CO CO CO CO CO l>t^t^ 28 HEIGHTS AND WEIGHTS OF SCHOOL. CHILDEEN. ^ si 1 XI «eococo S 5! ?SSS3 s s [-1 -ETJEA JO ^naiOBgaoo S3 ■spxmod 'nOI!('BlA8p pjBpuBijg •spimod '^qSiaM. uBaj^ CO i ' S : : "5 ocooo •uajpnxio JO jsqum^ §M o-* •sptmod ';qSraAi UBaj^ o j '■ o 3 CO OC CO cc t^ t^ CO CO "^ "^"0»O ■n9jp[Tiio JO jaqmnM i ji '- (N CO -BiAap pjBpn'Big OCOO;M r-HOCOCO 10 CO "^ CO •spimod '"mSidM. n«aH o '• '■ i ;S : : I 0"5 OiO iOC0 tocOcDCOCD cDcOOCOCO t^ t^ t^ 11.65 12.25 10.14 11.28 10.92 11.84 10.23 13. 89 12.87 13.46 24.69 6.91 7.47 6.43 7.30 7.23 8.51 7.45 10.97 10. 45 11.39 23.04 59.3 61.0 6.3.4 64.7 66.2 71.9 72.8 79.0 81.2 84.6 93.3 94.8 100.3 90.0 72.0 83.7 glSSSSS SS?gS??5 gj'O'^'cw c - - — 8.68 9.61 11.92 12.34 12.45 10.91 12.60 11.30 19.22 4.95 5.72 7.40 7.85 8.65 7.64 9.31 8.52 16.43 57.0 59.5 62.1 63.6 69.5 70.0 73.9 7.5.4 85.5 75.6 93.7 96.0 76.0 66.0 o 05 SSS|2 gigs??)"' o^^-H -- - 9.80 10.39 10.84 10.84 10.62 13.59 14.84 5.48 6.09 6.72 6.97 6.68 9.65 11.10 55.9 58.6 62.0 64.3 66.0 71.0 74.8 79.8 68.2 85.0 86.0 o 2 -* 9.11 9.98 6.73 7.02 5.10 5.74 4.11 4.26 56.0 57.5 61.1 60.7 63.2 78.3 59.3 •oo 888 " - COOSCO^Oi CO CO (N -< 55.4 56.2 58.7 63.8 58.6 o •6 o to oo»o^ - -' - 52.5 63.0 50.0 65.2 tOCC '-l'« -' ? kp ir J? ? £ S & 5 ? S CO 2 s CO 2 i IS s g p c r* 30 HEIGHTS AND WEIGHTS OF SCHOOL. CHILDREN. « I S -BUBA JO :)aaiotjjao3 •sptmod •spunocl ';q3raAV ueapi •najpijqa jo jaqnin^ -mi'BA JO ^uaTotjfaoo •spimod 'nonBiAap pjBpnB:>g •spimod '%v{3i9J&. HBapi •naipirqo jo jaqumj^ -BiiBA JO :jnaiDg:aoo j,toC-ocg> o>-ie •a •53 •sptmod 'noi^'BtAap pjBpnB^g •sprmod '^qSiaAS. vcedy^ •naipitqo jo jaqnrriN -BtJBA JO ^uaiogjaoo •spimod 'noijBiAap pj'Bpn'Gijs •spTmod 'jqgiaAi tiBapi ■naipnqo jo jaqnmjsj ■^^iiiq -■BiJBA JO luaiogjaoo •spnnod 'uoi-jBiAap pj^puB^s •spnnod '^qSiaA UBapl •uajpipjo JO aaqumjsi; 1 Si;:: ; ; ; i i \\ \': \ \ W W = i^ : : 35 ! ! ! ! ! I I I I !!!!.' III!! I I _h I I M I . . I I I I I I I I I I I I I I I I II I ! o I I I I ■ ; ' ' ; I I I .' I I I I I I ! I I I I t^ o I I ; ; I ; ; ; ; i i i ; ! ; ! : CO CO • ■ ; ; I ; I I ; I I I I Tjillll lllll II. o> lllll llo'' oj ' ' o • I I «5 ' ■ 05 ; • ' ■* u5 • • 00 I I I I lllll I I I rt I lllll I I _i I I (N lo • • ; ; lllll III I I I I I !>•;;; I I '. I I I I I I I I I I I I ', I ill 05 ' °° ' ' I I lllll lllll I I I I I . I I I I I >ra • • a> O • ; ■ I lllll lllll" lllll lllll t^ I I I I lllll OO 'lO oj I I I I lllll lllll I . . I . I^o •C'i p. rtoo -o ^ I I I I lllll lllll lllll l^rt '.c<> S : ; ! i i i i i i i i i i i i i i i i i i 'S Ill 111!! 1 I I I I III!! ^ I : : : : : i : : ; i i i ! : StQC-ooo* orHNcos "'sesisSS 2:2S3£23! !22Es222 ■•'iWWWC^ CQCOCOCOCO COCOCOCOCO -^ -.^ i^H ■.# -^ Ttl ■* ■'Jt -Tj* ^ HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 31 O i-H W CO Tt< lOOt^QCOi Q^MCQ-^ lOtPt^OOOS O i-i CM O O Ol CS »0 CO c^i c d o d o do 00 -J ^ Oi »o i-* ^' o c c t^ OC (N I S' c-i « ^ ro 00 "^ d CO O 1-H .-I ^ .-t -M !N CO C^|-^ 0CCiO«::50 CC-^CiQ d^ dd-^i-^d dccfN Cid i-ndiWc^^ 1-HiOiO r^r^OtCOs (;c OS O f-H o t>- »o ro O O OX'Ci^Oi OCiOO^ r-1— '(MC0(N CO CO -^ O r>- CO »C Ci CO O •-< b* CO ■^ c^ r-H 1-H CO CO lO lO -^ CO f-H l-H icoco-^co 'THr^co'^co T-io 1-- CC !:r Oi O O:. 'f h- -<*< Tt< 00 h* dro-^coci C^CO'3'COCO i-n—i CNJOXOO 05^00 53 t^xozooa : t~ CO lo CO Tt< -"i* t~. ' :r O o I^ C^ t^ 05 TJH CO -^ O O rooicc-^ ^_j«_c-> T-^^X'WO r^wcsoo^ ^ccut^»-i coo-* — i-H t-H-* -^ CC CTi «CMO< T-l— - CO lO CO "^ Cs C5 c5 cc i-< CO CO t^t^OOOOOO 0503 o>oti ^C^OOO lOOirt'OOiO CCCOOOIOOO QC't^C^' •-1 i-H N CO CO CO CO 00 : lO -^ M »-< CO CO c5 CO t-^oc oo 00iOt>- -JO ooS o o-^ o oi c4 ** c4 ■^ IS c^ cs to c>o -J JOO^^-H C0C^»O50CO3 OS O 00 ■'f C4CCOO CD -J oc C^ >-hC3 -^O C -^ :t»>ra o CO IN-Ht^O lO CO ■<»< C-J CO 05 CO oi o r^ CO CO CD CO CO t- t^ r- OC' 00 00 O: CT. I •o o o c6pe4 ^2?5SS S5SSS ■*?* 1— Ci -^ w; c<»T-t^-( ss ■3 "5 iC *0 (O CD CD CD 5D (C (D tD CD ^D t*»t*l>» 109764°— 22- 32 HEIGHTS AND WEIGHTS OF SCHOOL. CHILDREN. Table XVII. — Percentage distribution, according to height, of native white children in Maryland, Virginia, and North and South Carolina, by sex and age. BOYS. Height, nearest inch. Age at nearest birthday. 6 7 8 9 10 11 12 13 14 15 16 100.0 100.0 100,0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 26 27 28 .1 29 30 31 .1 32 33 34 .1 35 .1 .1 .1 36 .1 .1 .2 .2 37 38 39 .8 1.3 4.5 6.8 9.5 15.8 17.1 15.8 10.0 7.9 3.9 2.4 1.8 .8 .8 .3 .3 .3 1.1 .1 1.7 2.4 8.2 13.6 14.0 17.2 17.0 11.0 5.6 3.9 2.1 .7 .1 .4 40 .1 .2 .7 .8 2.0 4.5 7.5 12.4 17.4 17.0 12.5 11.2 6.6 3.8 1.7 .9 ,2 .2 .2 .1 .1 .1 ....... .9 2.0 4.8 9.3 13.5 15.4 15.7 14.3 10.7 7.1 3.5 1.0 .6 .1 .1 41 42 .1 • .4 43 44 .1 .3 .9 1.3 3.0 4.5 8.0 14.4 16.0 15.8 14.5 9.2 6.0 3.2 .9 .7 .5 .1 ....... .1 .1 .1 .3 1.1 1.1 3.6 6.4 11.1 14.7 16.1 13.4 10.4 9.1 5.6 3.3 1.7 .6 .2 .3 .1 .1 .1 ■■■■-■ .1 45 .1 46 47. 48 49 .4 .8 2.6 5.2 7.9 11.4 13.8 14.3 11.1 9.9 9.1 4.2 4.6 2.0 .8 .5 .4 .1 .1 .1 .7 .4 1.6 2.5 3.8 7.8 12.5 14.9 14.9 12.1 10.8 5.7 5.2 3.8 1.6 .9 ■■■■-■ .2 50 51 ... .8 1.9 3.0 4.9 7.9 12.7 10.0 11.7 9.8 9.6 8.1 5.5 4.2 4.2 1.5 1.9 .2 .4 52 53 54 .7 1.4 3.6 2.2 2.9 4.3 8.6 10.8 9.4 9.0 10.8 11.2 7.2 7.2 5.4 2.2 1.8 55 .6 56 57 .6 5S 3.1 59 .1 .6 60 5.6 61 :::::::: .1 .1 6.8 62 .3 5.0 63 7.5 64 13.7 65 16.1 66 — 11.2 67 .:::::: 11.2 6S 11.8 69 1 .1 .1 .1 4.3 70 1.2 71 72 .4 .7 .6 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. 33 Table XVIII. — Percentage distribution, according to height, of native rohite children in Maryland, Virginia, and North and South Carolina, by sex and age. GIRLS. Height, nearest inch. Age at nearest birthday. 6 7 8 9 10 11 12 13 14 15 16 All heights . . 100.0 .3 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 26 27 28 29 30 .3 .1 31 1 32 33 34 35 .3 36 .1 .1 37 .3 .3 2.0 3.4 4.8 11.6 8.2 13.3 15.0 13.6 9.9 6.2 5.9 1.7 .8 .3 1.4 3S .3 .1 .2 39 40 .1 .8 3.3 5.7 8.4 13.7 16.6 17.6 13.5 9.4 4.9 2.7 1.2 .7 .7 '"".2 .1 1.3 2.7 4.9 10.2 14.4 19.1 15.9 11.2 8.1 6.2 3.4 1.1 .4 .4 .1 .2 41 .2 42 .2 43 44 .3 1.0 3.3 6.2 10.1 12.9 15.3 17.1 13.6 8.0 5.7 2.9 1.4 .7 .6 .2 .1 .3 .4 .9 1.2 3.7 5.3 8.4 15.0 17.3 14.5 12.3 7.1 5.9 3.4 2.4 .5 .6 .1 .1 .1 45 .2 ■■■■■- .9 2.1 3.5 6.5 11.-2 11.2 14.5 13.9 9.8 10.6 6.1 3.8 2.7 .6 .5 .2 .2 .4 .1 .1 47 .2 .5 49 .2 1.1 1.6 3.4 5.0 10.3 10.3 10.3 11.8 12.5 12.4 9.2 5.1 3.6 1.7 .6 .2 .1 .1 50 .6 .3 1.4 1.4 3.6 5.0 5.6 9.2 9.8 12.2 12.4 15.3 8.3 6.5 4.0 2.6 1.0 .3 .1 .3 .2 .2 51 52 53 .9 .3 54 55 2.1 2.1 3.4 6.1 9.5 14.6 13.4 15.0 12.9 9.7 5.9 2.5 .9 .2 .2 .9 .9 1.2 3.0 5.1 10.0 10.6 17.8 16.0 13.6 9.4 5.1 3.9 1.2 .6 56 .1 .5 57 .3 .5 .2 .1 .5 59 2.7 60 8.2 61 .1 5.5 62 16.9 63 .1 18.3 64 15.1 65 16.0 66 .1 7.8 67 4.1 68 3.7 69 70 71 .3 72 1. 1 1 1 1 34 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. Table XIX. — Percentage distribution, according to veight, of native white children in Maryland, Virginia, and North and South Carolina, by sex and age. BOYS. Weight class. Age at nearest birthday. 6 7 8 9 10 11 12 13 14 15 16 All weights 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 2,5-29 30-34 .5 8.4 26.1 31.8 21.6 5.3 2.1 2.9 .8 .1 2.0 14.0 30.5 28.3 16.6 5.6 2.1 .3 .2 .2 35-39 .6 4.0 18.7 30.5 23.9 13.8 5.4 1.4 1.1 .4 ....... -■■■■- 5.7 22.0 24.2 22.0 13.6 7.4 2.4 .7 .7 .2 .1 .1 40-44 .4 45-49 2.2 7.7 15.5 24.3 20.7 14.2 8.8 3.5 1.7 .7 .5 .8 2.3 6.8 15.5 20.6 19.5 16.9 7.3 5.8 2.2 . 1.6 .7 .2 .1 .1 .1 .5 1.5 6.9 13.8 20.5 17.4 14.7 8.8 6.5 3.8 2.2 .5 .9 .5 .5 .4 .3 .1 .1 .1 .4 3.1 4.9 9.1 16.6 17.1 17.1 10.6 6.9 5.2 4.3 1.8 1.5 .9 .1 50-54 55-59 ....... 2.5 4.7 7.0 11.7 12.7 12.1 11.0 10.0 6.2 6.9 4.7 3.2 3.0 1.3 .4 1.3 .8 .4 .4 1.1 1.8 4.0 4.7 5.4 5.8 9.4 9.0 12.6 7.6 7.9 7.9 5.8 5.0 2.9 3.2 2.9 1.8 .4 60-64 65-69 .6 70-74 75-79 .6 80-84 .1 .1 .1 2.5 85-89 3.1 90-94 .3 .3 3.1 95-99 4.3 100-104 9.9 105-109 .1 9.9 110-114 8.7 115-119 13.0 120-124 7.5 125-129 11.2 130-134 . 9.9 135-139 9.9 140-144 3.7 145-149 .6 150-154 .6 155-159 160-164 165-169 170-174 175-179 180-184 .6 185-189 190-194 195-199 HEIGHTS AND WEIGHTS OF SCHOOL. CHILDREN". 35 Table XX. — Percentage distribution, according to weight, of native white children in Maryland, Virginia, and North and South Carolina, by sex and age. GIRLS. Age at nearest birthday. 6 7 8 9 10 11 12 13 14 15 16 All weights 100.0 100.0 100.0 .1 .1 .9 10.0 23.9 31.4 18.1 10.1 3.5 1.2 ...... .2 .1 .1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 25-29 30-34 2.5 14.7 28.6 32.0 13.9 4.8 1.7 .8 .3 ""i'.Q 21.4 36.2 24.1 8.3 4.1 .4 .4 .4 .1 35-39 .2 3.0 11.3 24.2 22.3 IS. 4 10.1 5.7 2.0 .9 1.1 ....... .1 .3 40-44 .9 2.9 12.4 20.0 21.8 17.3 11.1 6.1 2.6 2.4 1.0 .7 .1 .5 .1 1.3 4.3- 10.7 17.4 19.8 15.5 12.8 6.4 4.7 2.4 2.1 .8 .5 .6 .2 .1 .2 .1 1.0 2.7 7.8 13.7 14.4 14.5 11.4 13.3 6.2 5.5 3.0 1.6 1.6 1.4 .5 .4 .1 .1 .1 .1 .1 45-49 .1 .4 1.0 3.5 3.9 6.3 12.2 12.7 12.2 10.5 12.4 8.2 5.8 2.9 2.6 2.4 .9 .9 .6 .1 .3 .1 .5 50-51 55-59 .2 .6 .8 3.4 4.7 7.4 11.4 8.5 16.3 13.6 8.9 7.4 6.8 3.8 2.1 1.5 .6 .4 .4 .6 60-64 65-69 ;. . 70-74 .3 1.5 4.2 6.6 6.6 12.1 14.5 11.8 11.5 10.0 6.0 6.0 3.3 1.8 .9 .9 .6 .3 .3 .3 7.5-79 .5 80-8-1 .3 .9 85-S9 2.7 90-94 3.2 95-99 .3 6.8 100-104 11 105-109 16.0 110-114 16 115-119 .1 .1 12.3 120-124 . 1 . 8 7 125-129 10.0 130-134 « .1 .1 4 6 2.3 140-144 .5 .5 .1 .9 155-159 .9 .6 .2 5 16&-169 .5 170-174 .1 175-179 .3 180-184 .5 190-194 . _ _ .5 1 1 ' i 36 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. Table XXI. — Mean, median, and quartile heights and weights of native white children of Maryland, Virginia, and North and South Carolina, by sex and age. Age at near- est birthday. Mean. Boys. Girls. First quartile (Qi). Boys. Girls Median (Md). Boys. Girls Third quartOe (Qa). Boys. Girls 7 S 9 10 11 12 13 14 15 16 6. 7. 8, 9 10 11 12 13 14 15 16 STANDING HEIGHT (INCHES). 45. 4± 0.096 46. 8± .064 48. 8± .057 60. 7± .060 52. 6± .057 54.3± .064 56. 2± .073 58. 0± .076 60. 3± .119 62. 9± .156 64. 6± .159 44. 8± 0.115 46. 6± .063 48. 5± .057 50. 5± .060 52. 5± .062 54. 5± .070 57. 0± .072 59. 3± .081 61. 1± .088 62. 5± .097 63. 3± .114 43.1 42.2 44.7 44.3 46.3 44.8 44.4 46.5 46.1 47.9 46.8 46.4 48.3 47.9 60.0 48.5 48.3 50.2 50.0 5L9 50.5 50.3 52.1 51.9 53.7 52.0 52.0 53.7 53.9 55.6 53.7 54.3 55.5 56.7 57.7 55.6 56.8 57.4 69.1 59.3 57.4 59.0 59.7 60.8 62.2 60.0 60.3 62.5 62.0 66.0 62.4 61.4 64.4 62.9 66.4 WEIGHT (pounds). 47. 5± 0.269 60. 4± .162 54. 5± 59. 6± 65. 2± 71. 1± 78. 0± 85. 1± 95. 4± 108. 4± 116. 7± 45. 5±0. 261 48. 3± .156 62. 4± 68. 0± 64. 0± 70. 3± 79. 7± 89. 7± .420 99. 4± .433 107. 6± .607 113. 6± .740 ,171 ,208 238 298 353 42.4 46.0 49.8 63.9 59.6 64.6 70.0 76.5 83.9 95.1 104.9 41.0 46.8 44.4 49.9 47.8 63.9 62.0 68.9 66.7 64.7 62.1 70.6 69.3 75.7 78.4 84.1 88.2 93.6 96.6 107.7 104.4 117.6 46.0 47.9 51.7 56.9 62.3 68.4 78.2 88.3 9a 4 106.0 111.9 50.7 54.6 58.9 64.6 70.4 76.9 84.4 92.1 105.6 122.7 129.9 46.1 47.6 49.6 51.6 53.6 56.0 6&7 60.9 62.5 63.7 64.4 48.6 51.6 56.4 63.0 69.6 76.1 87.3 99.5 108.8 117.2 122.6 1 1 -o o o, IN ja u 2 _c a 2 3 "S u .S 2; 1 Z6-96 -^ •^ ee-t-e 1 £6-26 -^ 16-06 — 1 68-88 i8-98 S8-*8 £8-28 1 18-08 6i-^L U-9L 9l-fL - U-^L cj - Ti-Oi 6&-«9 o -- i9-99 (N - 99-f9 CO - CO S9-Z9 CO - T9-09 "O - 6e-8S r>. •* - j:5-9s ■o -^ (N SS-f5 05 TfICO £5-29 (Mf~ 0^0^ i ,1, Sm 4^ Regre sion weigh on height C^ -H ^ °a o -H-H S§ t^ o o" o a . oo '+3 !=" o -H-H ooo o o ■Hg gs CT .-« (3 o a. -H-H CO t^ s 1 i ira>o S -* -^ OC-H ^ ■2 gg -d fl.2 -H-H q t^ (N COrt) (NCO w § S X ^ ^•S' 1 o.a 1 ffl o 1 36 HEIGHTS AND WEIGHTS OF SCHOOL CHILDREN. Table XXI. — Mean, median, and quartile heights and weights of native white children of Maryland, Virginia, and North and South Carolina, by sex and age. Age at near- est birthday. Mean. Boys. Girls. First quartile (Qi). Boys. Girls. Median (Md). Boys. Girls Third quartOe (Q^). Boys. Girls. STANDING HEIGHT (INCHES). 7 8 9 10 11 12 13 14 15 16 45. 4±0. 096 46. 8± .064 48. 8± .057 50. 7± .060 52. 6 ± .057 54 3± .064 56. 2± .073 58. 0± .076 60. 3± .119 62. 9± .156 64. 6± .159 44.8±0.115 46. 6± 48. 5± 50. 5± 52. 5± 54. 5± 57. 0± 59. 3 ± .081 61. 1± .088 62. 5± .097 63. 3± .114 .063 .057 .060 .062 .070 .072 43.1 42.2 44.7 44.3 46.3 44.8 44.4 46.5 46.1 47.9 46.8 46.4 48.3 47.9 50.0 48.5 48.3 50.2 50.0 5L9 50.5 50.3 52.1 51.9 53.7 52.0 52.0 53.7 53.9 55.6 53.7 54.3 55.5 56.7 57.7 55.6 56.8 57.4 59.1 59.3 57.4 59.0 59.7 60.8 62.2 60.0 60.3 62.5 62.0 65.0 62.4 61.4 64.4 62.9 66.4 WEIGHT (pounds). 6 47.5±0.269 7 1 50. 4± .162 8 54.5± .160 9 59. 6± .181 10 65.2± .197 11 71.1± .235 12 78.0± .300 13 S5.1± .332 14 95.4± .545 15 108. 4± .828 16 116.7± .910 45. 5± 0.261 ?.3± 52. 4± 58. 0± 64. 0± 70. 3± 79. 7± 89. 7± 99. 4± .433 107. 6± .607 113. 6± .740 ,156 .171 .208 .238 .298 .353 .420 42.4 41.0 46.8 45.0 50.7 46.0 44.4 49.9 47.9 546 49.8 47.8 53.9 51.7 58.9 53.9 52.0 58.9 56.9 646 59.5 56.7 64.7 62.3 70.4 64.5 62.1 70.6 68.4 76.9 70.0 69.3 75.7 78.2 844 76.5 7&4 84.1 88.3 92.1 83.9 88.2 93.6 98.4 105.5 95.1 96.5 107.7 106.0 122.7 104.9 104.4 117.6 111.9 129.9 46.1 47.6 49.5 51.6 53.6 56.0 5a7 60.9 62.5 63.7 644 48.6 51.6 56.4 63.0 69.6 76.1 87.3 99.5 108.8 117.2 122.6 Table XXII. — Correlation between heights and weights of native white school children in Maryland, Virginia, North Carolina, and South Carolina. 380 6-YEAR-OLD BOYS. i Number of children in each 2-pound weight group. Height ber of rhll- dren. weight at earh height. nearest inch. I i I I i 1 1 % 1 1 1 1 1 I 1 1 1 I I 1 1 1 1 1 i 1 1 1 1 1 1 1 1 AU heights. 380 47.5 2 3 14 16 43 38 46 43 44 27 19 6 V 5 3 2 2 1 1 1 26 27 28 29 30 ! 31 32 33 34 35 36 37 38 39 3 36.0 1 2 1 40 5 43.0 1 1 1 1 1 ] ' 1 41 17 39.4 1 1 3 4 5 1 1 1 42 26 40.2 1 1 4 3 10 3 3 1 1 43 36 43.1 ■1. 2 8 9 8 2 4 1 44 60 45.1 1 1 9 16 10 8 3 8 2 1 1 1 45 65 45.7 5 6 4 17 12 11 7 2 1 1 - 46 60 47.6 1 4 ■/. 8 15 12 7 V 1 47 38 49.8 •1. 2 V B 9 7 3 48 30 52.6 1 5 8 6 5 1 i 2 1 49 15 55.9 1 2 4 2 1 50 9 59.8 1 ' 2 1 1 1 2 1 61 7 65.9 1 1 1 52 3 70.7 53 3 70.3 54 1 69.0 55 1 50.0 1 66 1 67 58 5E 6( 61 1 1 - ' 93.0 i 1 353 6-YKAR-OLD GIRLS. Mean weight at each height. Number of children in each S-pound weight group. Height nearest inch. her of chil- dren. I 1 1 I 1 % 1 1 ^ 1 1 1 1 I 1 I 1 1 I 1 1 s s ^ 1 I I 1 l|l i i I \ AU ; heights. 353 45.5 1 4 11 21 24 3» 37 63 47 29 28 16 10 6 7 2 2 4 1 1 1 1 26 1 41.0 1 1 27 28 29 1 30 1 36.0 31 32 33 34 ! 35 1 37.0 1 36 37 1 49.0 38 1 30.0 1 39 7 38.3 1 1 2 M 1 1 40 12 36.3 1 4 4 41 17 41.8 1 4 4 5 I 42 41 40.2 4 6 S 9 7 43 29 42.0 1 1 2 2 9 1 44 47 43.4 1 1 4] 8 9 15 4 2 1 1 1 45 63 45.3 3 1 3 9 16 48 48 46. 1 \ 3 7 13 47 35 22 21 49.2 2 3 10 1 5 8 3 1 1 1 1 ' 49 52.6 ^ 1 50 6 52.5 1 1 2 2 1 1 51 3 63.0 1 52 1 50.0 1 I 1 ! S3 M S 65.2 _ ' — — 1 1 55 1 56 57 1 96.0 68 69 CO 61 i 1 02 \ i ; 1 \ \ : \ ! '■ : : : '■ . ' Constants of height and weight for 6-year-old children. Height (Inches). Weight (pounds). Correlation ratio (n). Coeffldsnt of correlation Reisres- sionor wdfht on height. So.x. Mean. Standard deviation. Meui. Standard deviation. Boys 45.4 44.8 2.77±0.068 3.21± .081 47.5 45.5 7.76±0.I9O 7.27± .185 O.SIOlO.OlOe .788± .0136 0.783±0.013« .«75± .0195 2.l« 1.52 10»764»— 22. (Face p. 36.) No. 1 Z,8-98 £8-28 61-9L U-Zl XL-Ql 19-99 e9-w T9-09 1^-99 55-^ Ts-oe Gfr^f a-9f CT-e^ ie-9S ee^E S.sf 2 a "-a <- 8 c sst ' v^ ^^ i-H ^ tf'S^ ^ ^ °a oo 11^ el- d -H-H mo ls d ooo G . •^ c^ d •io -H-H n o^ SS d •oo •^ -ss -H-H §'E ft 0213 tod S •s s doo >o^ -d fl si ?^ o -H-H o .g SS m-a (N(N ■s OOO w COCO •A t» II 1 pq O I Table XXIII. — Correlation between heights and weights of native white school children in Maryland, Virginia, North Carolina and South Carolina 745 7-YEAR-OLD BOYS. Total Mean weight at each height. Number of children in each 2-poun(i weight group. | Height nearest inch. num- ber of chU- flren. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i 1 1 ^ 1 i ^ ^ \i 1 i 1 1 1 i j AU 1 1 heights. 745 50.4 1 7 8 29 49 73 89 91 112 81 60 50 32 24 13 13 4 4 2 1 1 1 — 31 1 57.0 1 32 33 34 35 36 1 60.0 1 1 ' ' 37 1 48.0 1 38 39 2 61.5 1 1 1 40 8 39.9 2 1 3 1 1 1 41 1 37.0 1 1 42 13 42.3 2 1 6 1 2 1 ] S 18 42.7 1 3 X 3 2 1 1 1 • 61 45.2 1 10 10 10 16 6 6 1 1 1 1 1 45 101 46.0 3 9 15 26 16 19 5 2 3 1 2 1 46 104 47.9 6 .'. 15 24 20 IS 8 •■> 2 1 47 128 50.7 1 2 11 14 19 37 23 10 5 3 1 1 1 48 127 51.6 1 1 4 12 21 2.-I 24 16 13 .1 3 1 1 1 49 82 55.1 1 1 3 3 12 13 14 10 12 ^ 2 4 1 1 60 42 67.5 3 5 6 S « 8 4 1 1 1 I 51 29 .58. 6 1 2 4 5 5 2 2 2 l! 1 1 1 52 16 69.9 3 2 4 1 I \ 63 5 58.6 1 1 1 1 1 1 54 1 56.0 1 1 1 1 55 3 61.7 1 1 1 56 I 1 57 58 59 1 53.0 60 61 i 1 735 7-YEAR-OLD GIRLS. Height nearest inch. Total ber of Chil- dren. Mean weight at each height. Number of children in each 2-pound weight group. 1 1 1 1 1 1 1 1 1 1 in 1 I 1 1 1 i 1 1 3 1 i 1 1 1 1 1 1 All heights. 735 48.3 3 10 21 58 60 99 103 103 93 66 39 22 18 19 6 8 2 1 2 1 1 31 32 33 34 35 1 1 36 1 56.0 1 III 37 I 1 38 2 47.0 1 1 39 i 1 1 40 1 36.0 1 ■ 41 6 40.3 1 1 2 1 1 1 1 42 24 42.4 2 3 K 3 3 •t 1 2 43 42 41.6 2 3 6 11 10 5 ■/ 1 1 44 62 44.0 1 6 8 9 20 8 7 2 45 101 44.5 3 4 15 12 32 16 11 4 1 1 46 122 46.8 7 15 21 29 25 15 1 1 47 129 48.8 1 5 .S II 29 311 21) 11 11 3 1 1 1 48 99 50.8 3 4 14 18 2.1 16 6 4 6 2 1 1 49 69 63.2 1 2 8 16 17 7 5 7 3 I 2 50 36 55.4 1 1 1 1 5 a 5 ? 3 1 2 1 51 20 56.2 1 •> 4 2 2 5 1 1 1 52 53 9 5 68.7 63.8 1 1 1 1 1 1 2 1 54 5 6S.6] j \ 1 i 1 1 1 1 1 56 1 1 1 1 ' 56 1 75.0 1 57 1 58 , 1 59 1 1 1 ' 1 1)0 , ■ 61 1 61.0 1 1 i ! i Coustants ot height and weight for 7-year-oId children. Height (incbes). Weight (pounds). Conelatlon ratio (■,). Coeffldent of correlation (r). Regres- Sex. Mean. Standard, deviation. Mean. Standard. de\iatloo. welght hefght. 4<.8 46.6 2.ss±ao>s 2.S3± .044 50.4 48.3 «.5<±0.115 «.26± .110 0.704±0.012S .r2i± .0118 0.6a3±a(U57 .6T9± .0134 Girls 1.68 lOBTM*— 22. (Face P.M.) No. 2 2^ :«l 11^ § 1 $ s* x: t> 0) a 1 2 o "5 fe .o j 'J0-f6 1 iH €6-26 1 16-06 1 68-88 LS-ys 1 58-W 1 £8-28 1 C< T8-08 1 IM 6i-8i 1 -^ U-91 1 n Si-tZ 1 t~ U-ZL 1 « u-oi 1 to 69-«9 1 o i9-99 1 n ?9-f9 1 « ■* 89-29 1 00 CO T9-09 1 g 65-8? 1 to is-9e 1 TO oc es-te 1 (M 65-25 1 c o 15-05 1 § 6t-8^ 1 o 00 Lf-9f 1 to 5t-W 1 £^-^» 1 •o \f-Of 1 o 6S-8S m ie-98 1 N 5c-^e 1 ££-28 ! I£-0£ 62-82 12-92 i 1 Mean weight at each height. 1 Total number of chil- dren. 3 05 Height, nearest Inch. oc So fefl « 2 SfgM s «5 Coeflacient of correlation So o -H-H S2 tot^ d Correlation ratio (v). 8S So d -H-H 00 w .-< »t^ d i o ft i 1 S.2 ■2 ^ d -H-H TOO) .-H TO 1 SS5 1 o G 1 1 1§ 03 > oo d -H-H i t»>o OCOO 02 > c a a •=. ■" 5 W Table XXIV .^Correlation between heights and weights of native white school children in Maryland, Virginia, North Carolina^ and South Carolina. 904 8-YEAB-OLD BOYS. Height, nearest inch. Total number of chil- dren. Mean weight at each Number of children in each 2-pound weight group. Height, inch. Total number of chil- dren. Mean weigh! at each height. Number of children in each 2-pound weight group. i 1 i 1 1 1 1 1 1 1 i 1 1 1 1 1 1 t 1 1 1 1 s 1 I 1 1 1 1 1 1 1 1 - - — All heights. 854 52.4 1 1 2 6 32 29 61 72 95 122 96 92 60 53 47 27 22 10 10 5 3 2 2 1 38 39 40 41 42 43 44 1 2 1 11 23 55.0 45.0 35.0 41.4 42.8 1 2 5 10 2 2 1 4 1 2 2 1 ■ 45 46 47 48 49 42 87 123 163 136 44.6 46.8 49.4 51.0 53.2 1 1 2 1 1 7 6 1 2 1 10 7 4 1 8 16 13 U 4 3 22 14 22 6 4 16 26 28 14 4 12 24 35 28 2 3 22 22 21 2 11 19 25 1 2 11 15 2 5 9 1 1 2 1 8 1 2 4 1 2 1 60 51 62 53 54 96 69 63 29 9 58.0 57.5 61.1 60.7 63.2 1 1 1 1 1 3 1 14 3 1 1 16 9 1 17 12 2 3 18 6 5 2 9 10 12 5 1 6 12 11 4 2 5 11 6 1 3 5 2 2 1 2 1 2 3 1 3 2 2 3 1 1 1 1 — — — 56 56 57 58 59 3 3 2 1 78.3 59.3 88.5 80.0 1 1 1 1 1 1 1 1 1 i ! ' 1 Constants of height and weight for 8-year-old children. Height (inches). Weight (pounds). Correlation ratio (v). Cocfflcient of correlation (r). Regres- Se.x. Mean. Standard „.„„ deviation. 1 *^®"- Standard deviation. weight height. 48.8 48.5 2.54±0.(M0 54.5 2.47± .040 52.4 7.13±0.113 7.39± .121 0.718± 0.0109 .751± .0101 0.682±O.0I2O .719± .0111 1.91 2.15 Qirls 109764°— 22. (Face p. 36.) No. 3 m^\ CQ & I o p. •g g i 2 2 o o V .Q "A i 1 1 1 1 1 1 1 U. n 1 1 1 1 1 1 1 1 1 1 90HK)I - eoi-ioT OOt-86 - 1 i-H 1 i6-56 ^6-26 N 16-68 1 IM 1 '^ "^ "* 88-98 1 C-) 1 e^ rt '"' 58-68 1 " - •-1 IN B8-08 >o 1 ^ ^ IN (N 6i-ii -»< ' -<-H0 u:>CD ^-..H-H Oi-89 s C<3 00O>Tt<00 ■*■* i:9-S9 05 M»OCOOOi 1 M< CO ^ ^■9-29 (N f1 COCSi -^(N i;© I— 1 t-( CS r-H CO W-65 § -HCOCO.-I rt -^ 8S-99 § IN lOOSt^i-l - es-£s § CO CO fH 1 S9-0S t^ CO .-< - 6^-i^ CO OICO 9*-ft 00 -^ CT-Tt - 1 0^-8S - ' ie-SE Mean weight at each height. CD i OSCD OCO O ooooocq o 86.0 106.0 O C30(N -.t CO iC»OCDCD CO Total number of chil- dren. •30 coSc^t~u3 OCOCDU5CJ -H ,-4 J3 S r-" Ss;s?s?s S5g5^SS 23S-2 .^ IN S 1 §§-s§| -4ei rt«s= .S o _, ent^ fflcieni rrelatio ir). oo -H-H eg o" d ■ g • s <=• oo «2 -H-H ^i 3!S p 2 t-t~ d * "w •H c O ft 11 d * ■H-H ^- coo ^ 1 g's coco X •2« ss .g d ■ -H-H M.O IN.^ o.!a n O I ?0-1?T i S. I XXV. — Correlation betu I heights and weights of native white school children in Maryland, Virginia, North Carolina, and South Carolina. 889 9-YEAR-OLD BOYS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 3-pound weight group. 1 1 1 1 1 1 1 1 1 1 I o E3 1 s 5 3 2 2 2 I s I s 3 s All heights. 889 69.6 1 1 13 39 17 129 129 120 112 93 66 29 26 4 1 — 23 29 30 31 32 33 34 1 03.0 1 35 36 37 38 39 1 I 4S.0 65.0 1 1 40 41 42 43 44 1 1 1 61.0 63.0 44.0 1 1 1 45 46 47 48 49 8 18 43 S3 120 46,5 49.9 521 62.8 64.3 1 1 3 4 2 5 2 2 6 7 8 9 2 3 19 32 37 3 7 24 29 2 4 4 26 2 6 9 3 4 1 2 1 SO 61 62 53 64 137 140 127 96 63 57.2 59.9 62 5 65.4 68.2 1 3 2 1 17 5 1 1 34 20 8 2 31 31 19 7 4 35 30 22 10 3 8 28 35 22 9 4 21 25 20 14 21 12 4 I 1 6 9 1 4 6 7 1 1 1 1 2 1 1 55 .56 57 58 59 31 9 5 1 1 71.7 75.2 71.4 89.0 55.0 1 1 1 1 1 4 1 8 1 2 7 1 5 2 3 2 1 1 I 1 1 60 61 1 02 1 "1 74.0 59.0 1 ^ 1 1 1 900 9-YEAE-OLD QIRLS. Height, nearest inch. Total number otchU- dren. Mean weight at each height. Number of children in each 3-pound weight group. 1 1 1 1 1 1 1 1 i 1 1 1 2 1 K 1 1 1 1 1 1 1 s s — — - — — — All heights. 900 58.0 1 1 18 42 69 122 151 107 127 78 62 .52 26 15 5 7 4 4 3 1 1 4 28 29 30 31 32 33 34 1 50.0 1 35 36 37 3S 39 40 41 42 43 44 1 2 3 80.0 59.5 45.0 1 1 1 1 1 1 46 46 47 48 49 9 30 66 91 116 47.9 47.0 49.5 51.2 M.l 1 1 9 6 1 6 8 12 10 4 5 13 21 17 1 4 12 23 27 1 2 5 IS 30 1 1 3 11 16 1 4 15 1 1 9. 1 2 1 1 1 1 1 1 t 50 51 52 53 54 138 164 122 72 51 55.9 58.6 62.0 64.3 66.0 1 9 3 30 16 5 1 1 37 37 10 7 3 22 25 19 7 1 19 34 31 12 10 13 12 24 12 6 3 15 13 10 9 3 8 9 14 8 2 5 5 6 1 3 1 4 1 1 2 1 1 1 2 1 1 i 65 56 57 58 59 26 13 6 5 2 71.0 74.8 79.8 68.2 S5,0 1 1 1 6 4 3 1 4 4 4 1 1 2 2 1 1 1 2 2 1 2 1 1 1 1 1 1 60 61 62 63 1 86.0 105.0 I 1 1 1 1 Constants of height and wei^t for 9-7ear-old children. Height (inches). Weight (pounds). Correlation ratio (i,). Coefficient of correlation (r). Regres- Sex. Mean. Standard deviation. Mean. Standard deviation. weight height. 50.7 60.5 2.66:1:0.043 2.69± .043 69.6 68.0 7.93±0.12S 9.24± .147 0.744±a0101 .724± .0107 0.643±0.ai33 ! 1.92 .661± .0127 227 199764°— 22. (Face p. 38.) No. 4 " 1 1 I i I- § 1 o a a o "S 1 oei-szi - IZISZI f'Zl-ZZl ' ISI-6II 811-911 en-en -^ 211-011 60I-Z0I - - 90I-W)I - -^ fiOI-TOT 001-86 - -HIM i6-S6 ■^ -< -« 1-6-26 ^ -< - 16-68 >o (M - 88-98 x c« S8-E8 ■* o-*c^ 28-08 S M -;?g^"' OrH^—l Height, nearest inch. 42 ^sss CD O CO O CO ss 1 ." U- .LJ Regres sion weigh on height CJCS »^ e<5K5 °a ■^ o c5 * -H-H gg |s o ■ "tiO a . •.3 p d ■ "a o +I-H 005 =5 • ^ ■sg •V §.2 d * o ft ^^ -H-H Old ja •^ ^ g (M o s CD CO ^ ■2 « ss .4 fl.S o3 > d -H-H .g S§? Wt3 Niri •a .-s 1 o.!a 1 n o 1 Table XXVI. — Correlation between heights and weights of native white school children in Maryland, Virginia, North Carolina and South Carolina. 973.— 10-YEAR OLD BOYS. Height, nearest inch. Total number ot chil- dren. Mean weight at each height. Number ot children In each 3-pound weight group . 1 . — . 1 1 5! 1 1 1 1 1 1 I 1 1 S 1 " S 1 1 1 ^ 1 1 g i s i ^ 1 t I 1 i s ^ — — — — — AU heights. 973 65.2 1 8 13 47 59 86 127 143 128 128 63 73 33 27 14 8 5 4 4 1 1 3.5 36 37 38 39 1 65.0 1 — 40 41 42 43 44 1 1 37.0 45.0 1 1 4.5 46 47 4S 49 3 9 13 45.0 50.2 51.6 55.1 55.4 3 2 2 1 2 3 4 4 3 8 11 1 4 8 8 1 6 9 1 1 2 8 4 1 1 1 50 51 52 53 54 78 140 156 154 141 58. 4 60.7 64.0 66.5 68. 2 1 1 1 11 5 2 2 1 12 15 5 1 2 15 30 17 6 16 27 33 23 12 12 36 39 30 13 8 11 22 36 32 2 10 21 31 33 2 8 16 14 1 1 4 7 13 1 6 6 2 1 2 2 3 1 2 2 1 1 55 56 67 58 59 90 58 31 9 7 71.6 74.5 77.9 76.7 84.4 3 1 1 2 2 5 2 2 10 4 1 1 21 8 1 11 8 3 1 21 15 8 1 1 5 9 4 1 1 6 3 5 2 1 4 2 3 1 2 2 1 1 1 2 1 1 1 1 1 1 60 61 62 63 64 1 2 79.0 95.0 72.5 1 1 1 3 1 1 ) 65 66 1 i ID-YEAR OLD GIRLS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 3-poimd weight group. 1 o 1 1 2 1 100 107 1 136 107 i p S2 I e; 1 1 1 1 1 1 s i 2 S X o 2 S 2 2 S i I AU heights. 936 64.0 1 5 11 18 57 104 91 51 61 16 11 21 12 5 6 5 3 4 1 1 1 1 35 36 37 38 39 1 50.0 1 40 41 42 43 44 2 3 53.5 61.3 1 1 1 1 1 46 46 47 48 49 4 8 11 35 50 60.8 45. S 50.8 52.7 54.7 3 1 1 3 1 4 1 1 3 5 3 1 4 5 10 1 1 1 12 15 2 4 10 3 6 2 2 1 1 1 50 51 52 63 54 79 140 162 136 115 57.0 59.5 62.1 63.6 69.5 1 1 2 3 1 13 10 5 5 19 15 20 13 1 17 23 21 15 7 14 46 35 18 6 6 IS 31 27 13 7 8 18 23 21 6 15 14 27 1 1 7 7 12 4 3 8 16 3 2 2 2 1 4 1 1 1 1 1 1 1 1 1 65 66 66 66 70.0 73.9 1 ' 2 3 4 8 14 9 14 6 7 10 9 10 2 4 1 2 5 4 2 1 1 I 1 1- 1 M 1 ^■.a > 1 1 ' 1 ^ 2 ' " ' ^ ' ' j 60 61 62 63 64 1 1 1 93.7 96.0 76.0 66.0 1 1 1 2 1 1 1 1 65 66 1 94.0 1 Constants of height and weight tor 10-year-oId children. Height (inches). Weight (pounds). Correlation ratio (,). Coefficient of correlation (r). Regres- Sex. Mean. Standard de\iation. Mean. Standard deviation. welght height. 62.6 52.6 Z64±0.Oi0 2.S3± .044 65.2 64.0 9.09±0.139 10.79± .168 0.720±0.0104 .709± .0110 0.693i: 0.0113 .660± .0125 2.38 2.52 Girls 109704"— 22. (Face p. 36.) No. 5 - 1- cs d 3 ! o p. 1 a> C C (U 1 "o k. a- 1 1 J 1 1 1 i 1 1 1 1 1 IZI-«9I 1 i9l-19t 1 - £91-091 6GX-9SI j 1 SSI-ZST ! 1 1 lSX-8?-! -' iH-tl-T 1 £H-0f-I 1 6£I-9£I 1 1 5£T-2£I 1 \z\-^z\ iz\-^z\ i Esi-oei 1 - -^ 61MIT 1 '* eii-sii 1 - (N — 1 -H .-( I 11-801 1 0« -H '^ iOI-fOl 1 •* ^ £01-001 1 ^ —1 CO 66-96 1 » -o — «-< c6-g6 1 CO - CO «« CO ^co 16-88 1 -•05«OC<5 ^^ i8-t8 1 ■* ■50"*CO lO-Hrt -^ 88-08 1 Oi-9i 1 .;>--j50t~ -cosCO ■* -1 '^.l-Zl s ~j.o.co m -' Ti-89 1 ?:; 5=c«-. ~ i9-t9 1 89-09 1 ^t^coco - CIO 65-9S 1 or 9S-SS 1 S 1 -^ i^-st- 1 o 1 Vr^\ ' =o i 85-0^ 1 weight at each height. t- - (COCO® 93.3 94.8 100.3 90.0 72.0 S3 5 « 2 s «?8S53 mm-* CO CO CO 3 d ^1 2 ^SoSS I «5 egres- on of eight on eight. coci «K& XI ^ 0"0 °c •ti o 00 c5 * -H-H Ig^ t^i^ too oco CI . 00 •Ic -H-H £3 SS t^to d to-^ .-i ■2 B rt CO tS +1+1 a CO 00 w^ OC> a ■ -H-H 03 t- 5S 4j> i-H ?H J3 s d 01^ ^ s s □0 Oi CO .-^ ss ■ -H-H g S8 coco Si tuo » fl a 1 Sfe >< a> OQ ^ 1 » J r Table XXVIII. — Correlation between, heights and weights of native white school children in Maryland, Virginia, North Carolina, and South Carolina. 781 12-YBAR OLD BOYS. Number of children in each .5-ponnd weight prroup. Height. Total number Me.in ot chil- ?! « ^ s C4 ^ CO ■A ^ io dren. height. I 1 I s I I s S t I i I i i i 'i l i k i 'i 'i i — — — — — All heights. 781 7S.0 4 12 64 108 160 136 115 60 51 30 17 4 7 4 4 3 2 1 44 1 70.0 45 46 2 55.5 1 1 47 1 79.0 1 48 49 3 61.7 1 1 1 50 6 64. S 1 1 ?. 1 1 51 20 65.4 8 2 2 1 1 1 62 41 66.4 V 13 15 8 1 •/. 53 62 68.1 •> 16 IS IS 6 1 1 54 89 70.8 1 7 27 36 11 6 2 55 108 73 1 1 23 37 26 8 6 2 1 1 56 112 T7.6 l.i 2.T 311 22 13 4 2 1 57 87 79.8 3 Hi ■« '^1 1(1 3 2 2 1 58 77 81.8 1 4 9 15 22 13 7 3 2 1 59 71 87.0 1 4 12 21 7 13 4 ."i ■I 1 1 1 60 33 87. .i 3 2 5 10 6 6 1 r 1 1 1 1 61 35 92. S 2 7 4 10 .■■. 4 1 •i 1 62 16 100.3 2 4 4 2 1 2 1 63 6 105.2 1 1 1 ■I 1 64 4 106.5 1 1 1 1 1 65 3 118.7 1 1 1 1 66 1 115.0 1 67 1 96.0 1 6S 69 1 90.0 1 1 ! 805 12-YEAR OI/D GIRLS. Height, nearest inch. Total of chil- dren. Mean weight at each height. Number ot children in each 5-pound weight group. 1 1 1 1 1 1 1 1 S 1 1 I 1 3 S 1 13 3 3 i i I 3 i 1 i 1 i All heights. 805 79.7 2 1 8 22 63 110 116 117 92 107 60 44 24 13 11 4 3 1 1 1 1 1 : 44 45 46 47 48 49 1 1 2 44.0 56.0 62.5 1 1 1 1 1 60 51 52 53 64 9 13 27 40 83 66.0 62 6 61.7 67.5 69.0 1 1 1 2 3 2 3 6 4 3 3 8 12 18 1 1 10 11 27 1 1 7 19 1 1 2 ; 3 8 1 4 2 1 1 4 55 66 67 68 59 83 83 95 101 100 71.1 74.5 79.4 82.4 87.0 1 3 11 4 3 3 24 19 8 5 2 24 21 21 16 2 7 22 19 22 21 7 9 18 14 18 6 1 1 5 1 10 ' 4 16 ; 9 26 1 9 2 1 6 13 3 3 2 1 2 1 2 1 2 1 60 61 62 63 64 74 41 29 14 89.5 93.6 99.4 100.2 107.6 1 1 1 2 1 13 2 11 4 1 2 16 7 3 4 10 9 7 6 7 7 1 1 5 6 2 1 2 1 2 2 3 1 3 1 3 2 2 1 2 1 1 1 1 1 1 1 65 2 113.5 2 1 1 68 69 ' ' Constants of height and weight for 12-year-old children. Height Cinches). Weight (pounds). Correlation ratio (ij). Coefficient of correlation (r). Regres- Sex. Mean. Standard deviation. Mean. Standard deviation. weighf height. 56.2 57.0 3.03±0.052 3.02± .051 78.0 79.7 I2.43±0.212 14.S5± .250 0.736±0.0111 .719± .0115 0. 706±0. 0121 .703± .0120 Girls 3.44 I09764°— 22. (race p. 36.) No. 7 s ffX-O^l 6EI-SST fST-oei 62I-52T izi-ozx 6n-^TT 60T-S0T tOT-OOI f6-06 6i-^i n-OL 69-59 ^9-09 65-59 w-os 61-Sl' K S5< ^ r-H W M d ^t^ ^ §g ■s^ II 5 ^^ d • 4)-H a 03 > S2 "S ■® c5 W 1 lOiO ^^•S 1 c: .!a 1 1 W o 1 as g- rS XXIX. — Correlation between heights and weights of native while school children in Maryland, Virginia, North Carolina, and South Carolina. 679 13-YEAB OLD BOYS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 5-pound weight group. 9 1 1 1 1 ^ ^ S8 1 1 1 o s i S z i 1 i i 9! i 1 i 1 1 All heights. 679 85.1 1 1 3 21 33 62 113 116 116 72 47 35 29 12 10 6 1 1 46 48 47 48 .49 1 1 81.0 87.0 1 1 1 50 51 52 53 54 5 3 11 17 26 77.0 67.0 65.9 67.4 73.7 1 1 1 2 6 3 1 5 7 3 2 5 1 1 1 2 3 1 1 1 1 1 1 i 65 56 57 58 59 53 85 101 101 82 74.8 1 78.4 1 82.1 1 84.0 87.4 1 3 1 7 7 4 1 16 19 9 6 1 17 28 24 22 9 5 14 27 2S 21 4 9 19 20 24 4 8 7 13 1 1 5 7 1 3 3 3 1 2 1 1 2 1 60 61 62 63 64 73 39 35 26 11 91.2 94.8 99.1 104.3 101.2 1 1 2 1 11 3 I 19 4 5 2 1 20 14 3 2 9 4 8 4 2 5 6 9 2 1 3 5 4 9 3 2 1 5 3 2 1 3 1 1 65 66 67 68 69 6 1 1 113.3 123.0 100.0 1 2 1 2 1 1 i 70 1 116.0 1 1 j_ : 69 5 13 YE AR OLI ) G RLt _ 1 ■ I 1 i ■ m m m m . . i mm m Height, nearest inch. Total number of ciiil- dren. Mean weight at each height. Number of cliildren in each 5-pound weight group. 1 1 1 1 1 1 86 8S 85 1 73 86 3 i 67 40 20 3 1 i 3 i 3 1 1 i 1 All heights. 695 89.7 1 3 7 24 27 a 18 17 6 6 4 1 2 j 1 45 46 47 48 49 1 1 50 51 52 53 54 4 2 10 10 25 86.5 63.0 66.4 74.8 69.4 1 2 1 3 2 4 1 9 1 1 1 9 1 1 1 1 2 2 1 1 1 1 2 1 1 1 1 55 56 57 68 69 35 39 64 68 86 70.6 76.3 81.4 83.9 86.9 1 1 8 1 1 6 4 3 2 10 9 9 8 4 9 11 19 15 U 1 6 16 14 18 1 4 5 13 17 1 6 7 14 2 3 13 2 4 7 1 1 1 1 1 60 61 62 63 64 86 106 68 46 28 92.0 96.5 100.4 104.4 105.0 1 10 4 1 1 13 14 3 1 20 11 9 3 1 11 16 8 4 3 12 21 15 11 4 6 18 5 4 7 5 12 4 8 4 2 3 i 6 1 1 3 4 5 1 2 1 2 4 1 2 1 1 1 1 1 1 1 1 1 1 65 66 67 18 7 2 113. 8 115.7 125.0 2 1 1 1 4 1 2 2 2 3 2 1 1 1 1 1 1 OS 69 2 95! ^ 1 1 1 70 i I Constants of height and weight tor 13-year-old children. Height (inches). Weight (pounds). Correlation ratio (,). Coefficient of correlation (r). Regres- Sex. Mean. Standard deviation. Mean. Standard deviation. weiKht height. 58.0 59.3 2.93±0.054 3.16± .057 85.1 89.7 12.&4±0.235 16.41± .297 0. 72O±0. 0125 .707± .0128 0.68r±0.0137 .609± .0141 109764'— 22. (Face p. 3«.) No. 8 1 § o 5" •s C3 a G G 3 o o u 1 1 1 1 1 69I-S9I 1 - WT-09T - "■^ 6St-^I 1 wi-oei 1 -- ett-et-x 1 ■* - ^ H'l-WT to ^ ^ eei-cei | N - --H f«i-oei 1 o -H ^(N «-H 6ST-SST ■^f W -^ l-H CO - -H f-SX-OST lO — IrHCOW^ IMiOrt 6XX-SXX 1 c^ N •o m ■* Oi t^ ^^^^ txx-oxx 1 00 ^_H iO-« 68-S8 j g 00 t~ CO t^ CO CO 1^ -^ »8-08 1 s i^to t^co^o.-i - 6i-«i ?? eot^ -^N M-^l ?5 ^5M 1 ^§ gfeS|2 ot^co^or-; ^ ^ ,-t w CI 3 c Hi ^ ; ImS r^St^toS -HCO»C^^ CO^ .2 « 2 ^1 < i_ ^ ISS OCDCCCO CO c5co 5 2 1 1 I 1 i ' 2 5 1 1 1 3 1 1 1 1 i 1 Constants of height and weight for 14-yesr-ald children. Height (inches). Weight (pounds). Correlation ratio (,). Coefficient of correlation (r). Regres- Mean. Standard deviation. Mean. Standard deviaUon. wcight height. 6a3 61.1 3.83±a084 2.9»± .062 95.4 99.4 17.52±a385 14.75± .306 asi6±a01M .6921 .0153 a795±aoii4 .»43± .0172 3.66 Oliis.. 109764*— 23. (Facep. 3«.) No.» 5 ^5 -9 L 1 p. § 1 s [S 73 C § C c 2 •a 1 o (U z 1 1 1 1 - 1 1 1 6iI-SiT fil-Oil 691-S9T - 1-9I-09I esT-eei I " - 1 WT-OST 1 -- ei'X-si^T 00 WT-Otl . eei-eei 00 rf^ t£T-0£T 3 COrf-H 6sx-^e;i o CO.-ICO— (M KKM-H f-SI-OST i j-l-H)N 6XT-^II « 1 COCOC^l -1 tll-OTT (N -^MCl 60I-S0T CO K)X-OOT j>o « s ^^ OOl . "So 1 5 ^ d +I-H iCOJ .s ooo CO i ^ i i i ^ i ^ s i k [t — — - — — — AU heights. 278 108.4 1 1 1 3 5 11 13 15 16 26 25 35 21 22 zt 16 14 8 9 8 5 1 i 42 1 42.0 1 ! ~ 43 44 45 46 47 48 49 1 50 51 1 55.0 1 52 53 54 2 66.0 1 1 55 4 70.5 2 r 1 56 10 79.6 2 4 3 1 57 G 80.0 1 1 2 2 ] 58 8 80.4 1 3 2 1 1 69 12 89.7 2 1 2 3 3 1 60 24 95.5 3 3 3 10 2 2 1 61 30 99.7 2 .■> 4 5 5 .') 2 1 1 62 26 106.5 3 2 5 V 3 4 1 1 63 25 105.8 1 1 4 V 5 1 4 1 1 64 30 112.8 1 1 2 9 6 5 6 1 1 1 65 31 119.7 1 2 3 6 4 6 3 2 3 1 1 j 66 20 124.4 1 2 1 3 3 3 3 1 2 1 67 20 129.4 1 2 2 2 4 3 2 1 3 68 16 133,0 1 5 1 69 6 130.3 1 1 1 1 1 1 70 5 138.2 1 1 1 1 1 1 71 72 1 2 148.0 1 1 1 331 15-YEAE OLD GIBLS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 5-pound weight group. 1 1 1 1 1 1 1 S i 1 1 1 s i s i S i a ?! i 3 3 3 i I 3 i S3 S 3 S i 1 3 — — — — - - - All heights. 331 107.6 i 1 1 5 1 14 22 22 40 48 39 38 33 20 20 11 6 3 3 2 1 1 1 1 42 43 44 45 46 47 48 49 50 61 52 53 64 1 157.0 1 55 56 57 68 59 3 3 4 10 17 101.7 85.7 96.0 90.6 92.9 1 1 1 1 1 3 3 1 1 5 2 3 1 2 3 4 1 1 1 1 1 60 61 62 63 64 33 35 69 53 45 101.6 99.9 107.6 107.1 113.6 ! i 2 i M 4 2 1 1 5 5 2 1 1 3 2 5 7 1 4 11 10 5 5 3 10 9 9 1 4 9 8 9 2 5 9 8 1 2 1 6 1 4 1 1 2 6 1 3 2 1 ! 1 1 : 1 1 1 j 1 1 1 1 1 1 65 06 67 68 69 17 13 2 lit 5 124.3 13.5. 125.0 1 1 1 i i ■ 3 2 2 3 2 3 2 1 3 3 3 1 1 2 ■ 1 1 I 1 70 71 72 99.0 1 1 1 1 Constants of height and weight for 15-year-old children. Height (inches). Weight (pounds). Correlation ratio (ij). Coefficient of correlation (r). Regres- sion of weight height. Se.x. Mean. Standard deviation. Mean. Standard deviation. 62.9 62.5 3.85±0. 110 2.62± .069 108.4 107.6 20.46±0,6S5 16,3S± .429 0.853±0.0110 .543± .0262 0,842±0,0118 .427± .0303 oiri;::::: 1764°— 22. (Face p. 36.) No. 10 Number of children in each 5-pound weight group. 1 1 1 I 661-561 r (•61-061 1 681-581 1 f8I-08I 6il-5il 1 tLl-OLl 1 1 691-591 1 1-9I-09I 1 1 6ei-ssi 1 1 KT-OSI 1 - 6n-9n 1 nx-cn 1 CD i 6ST-fi8I 1 2 ! »ei-OEi 1 2 6ZI-SSI 1 00 j ^SI-OZT 2 6TT-sn 1 N m-OTT .^ 1 60T-eOT 1 to 1 1 wt-ooi 1 o ! 66-56 f- t-6-06 1 lO 68-58 1 ■o f8-08 ■^ 1 6i-5i - I H-OL 69-59 - t9-09 1 65-55 1 *S-05 1 6?-S^ Mean weight at each height. Total number of chil- dren. to 1^1 •« Si ^1 1^ So fee m 52 d ■ -H-H §2 oo d ■ -H-H d • I 5;?3 to-o d ■ -H-H 1 C^cO dco 1 1 II Si d ■ -W-H c4c4 S toco 03 > c C o i |ilf Table XXXll. —Correlation between heights and weights of native white school children in Maryland, Virginia, North Carolina, and South Carolina. 161 16-YEAR OLD BOYS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 5-pound weight group. 1 1 1 S 1 s 1 1 1 1 1 3 i i 3 i i i i i s X i s 1 I s i 2 3 i 1 § g i ! AU heights 161 116.7 1 1 4 5 5 7 16 16 14 21 12 18 16 16 6 ' 1 1 47 4S 49 50 51 52 53 54 55 56 57 SS 59 1 1 5 1 103.0 79.0 83.0 85.0 1 1 2 1 1 1 60 61 62 63 64 9 11 8 12 22 103.2 98.0 104.9 1M.8 116.9 1 1 1 1 1 2 1 1 1 4 1 1 5 3 2 3 2 1 2 3 1 3 2 1 2 6 1 1 1 1 1 2 2 1 65 66 67 68 69 26 18 18 19 7 117.0 124.3 123.6 137.2 131.1 1 1 6 1 1 2 1 2 5 2 3 2 3 5 3 1 1 1 2 3 4 3 1 3 3 5 1 4 1 1 1 70 71 72 2 1 13S.0 130.0 1 1 1 ^^. i. ^ J J J 219 16-YEAR OLD GIRLS. Height, nearest inch. Total number of chil- dren. Mean weight at each height. Number of children in each 5-pound weight group. 1 1 1 1 I s 5 I 1 1 1 s S i s s i s i 1 1 i i s i s 2 i i i i 1 All heights. 219 113.6 1 1 2 6 7 15 24 35 35 27 19 22 10 5 1 1 2 2 1 1 1 1 1 47 48 49 50 51 52 53 54 1 45.0 1 55 53 57 58 59 1 1 1 6 77.0 88.0 82.0 97.8 1. 1 1 2 2 1 1 — — I 60 61 62 63 64 18 12 37 40 33 104.4 102.0 113.3 111.6 113.6 1 2 1 2 1 3 3 4 2 3 3 2 6 6 4 6 4 1 10 6 1 1 9 6 1 8 3 5 1 1 1 3 2 1 3 1 4 1 4 2 2 2 1 1 05 ' 35 03 i 17 07 1 9 08 : 8 69 1 118.6 125.0 126.6 133.4 1 1 2 4 3 1 9 1 1 6 4 5 3 2 1 6 5 2 1 1 1 1 1 1 1 1 1 1 1 71 72 1 — - / i ■ ■ ■ — " Constants of height and weight (or 16-year-old children. Height (inches). Weight (pounds). Correlation ratio (nj. Coef&cieDt of correlation (r). Regres- sion of Sex. Mean. Standard de%Tation. Mean. Standard deviation. weight heigh.. 64.6 63.3 2. 99±0. 112 2.50± .081 116.7 113.6 17. 12±0. 644 16.24± .523 0.7S4±0.0205 .592± .0296 0. 736±0. 0244 .o65± .0310 4.24 Girls 109764*— 22. (Face p. 36.) No. II o