Question

What is the value of the 30th percentile of the set of data: `18, 9, 7, 5, 11, 7, 17, 20, 19, 2, 17, 12, 5, 1, 13, 12, 11, 15, 16, 20`?

Answer 1

`30th` percentile is `6th` item i.e. `7`

Explanation:

To calculate the percentile of a data set, we should first order all the values in the data set from smallest to largest.

The data now looks like `{1,2,5,5,7,7,9,11,11,12,12,13,15,16,17,17,18,19,20,20}`

As their are `20` data points and `30%` of this is `20xx30/100=6`.

Hence `30th` percentile is `6th` item i.e. `7`