A Study On Normality of the Standing Height in the Japanese Youth

To examine whether or not the frequency polygons of the standing height in 296, 799 Japanese youth, 6 through 21 year-old boys and girls, are the "bell-shaped" normal curves, the normality-test analysis with reference to k-statistics is carried out on the frequency distributions of the standing height. In this test method, four nonnormal frequency distribution types which deviate from the normal curve are positively and negatively skewed, leptokurtic and platykurtic ones. The purposes of this study were: 1) to recognize what sorts of frequency distribution are contained in the standing height frequency distribution of the Japanese youth groups by the normality-test procedure; 2) to determine which growth curve (distance, velocity or acceleration) is similar to the skewness coefficient curve from 6 to 21 year-old subjects. The conclusions are: 1) the frequency distribution curves of 9 year-old boys and 16, 18, 20 year-old girls show nonskewness and mesokurtic curves; 2) only male senior high school and female junior high school subjects have negatively skewed distributions; 3) almost all Japanese youth groups have leptokurtic distributions, but 13 year-old boys and 11 year-old girls have platykurtic ones; 4) the phenomena of the maximum positive and negative skewness appear at the age of 11.5 and 14 in the male and 9.5 and 12 in the female; 5) the changing phases of skewness coefficient with reference to the ages in both sexes are similar to their own growth acceleration curves

Distribution (mathematics) · Kurtosis · Mathematical analysis · Normal distribution · Normality · Normality test · Skewness · Statistical hypothesis testing · Statistics · Demography · Mathematics · Physical Education and Training Studies · Sports and Physical Education Research