For a group of n = 250 subjects, 40th percentile would be the following value ?

Ans. is 'c' i.e., 100th Percentile (Centilel Centi les are values in a series of observations arranged in an ascending order of magnitude "which divides a distribution into 100 equal pas" So, number of interception required are 99, i.e., there are a total of 99 percentiles. Median is 50th centile. n percentile implies that (n -- 1)% of values are below it and (100 -- n)% of values are above it e.g. 40th percentile means 39% (n -- 1 = 40 --1) values are below it and 60% (100 -- n) values are above it. From above figure you can easily understanded The values below 40th centile are upto 39th centile (39%) Then comes 40th centile itself. 60% values (41-100) are above it. In general