Explain the meaning of the following percentiles.

(a) The 15th percentile of the head circumference of males 3 to 5 months of age is 41.0cm.

(b) The 90th percentile of the waist circumference of females 2 years of age is 52.7cm.

(c) Anthropometry involves the measurement of the human body. One goal of these measurements is to assess how body measurements may be changing over time. The following table represents the standing height of males aged 20 years or older for various groups. Based on the percentile measurements of the different age groups, what might you conclude?

Percentile

Age 10th 25th 50th 75th 90th

20 - 29 166.8 171.5 176.7 181.4 186.8

30 -39 166.9 171.3 176.0 181.9 186.2

40 -49 167.9 172.1 176.9 182.1 186.0

50 -59 166.0 170.8 176.0 181.2 185.4

60 -69 165.3 170.1 175.1 179.5 183.7

70 -79 163.2 167.5 172.9 178.1 181. 7

80 or older 161.7 166.1 170.5 175.3 179.4