Question

From the set of 20 observations find the 50^th , 80^th and 90^th percentiles.

9,6,12,10,13,15,16,14,14,16,17,16,24,21,22,18,19,18,20,17 (6 marks).

Answer 1

first you list them in ascending order:-

6,9,10,12,13,14,14,15,16,16,16,17,17,18,18,19,20,21,22,24

The 50 th percentile = middle number = mean of 16 and 16

50th percentile = 16 Answer

80th percentile = 19 and 90th = 21