18 9
The graphs, on this page and the next page, show height growth curves for girls and boys in the USA. The lines show percentiles. For example, the top line shows the 95th percentile. This means that 95% of girls or boys are at or below that height. Girls, 2 to 20 years
height in cm
200 195 190 185 180 175 170 165 160 155 150 145 140 135 130 125 120 115 110 105 100 95 90 85 80 75
95th 90th 75th 50th 25th 10th 5th
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 age in years (a) At what age is there most variation in the heights of girls? Explain your answer. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2]
Š OCR 2013