Question

{8, 15, 9, 18, 9, 17, 22, 10, 11, 9, 13}
What is the interquartile range of the data set?

Answer 1

IQR = 8

Explanation:

The interquartile range (IQR) is the difference between the upper quartile Q₃ and the lower quartile Q₁

We require the data arranged in ascending order and to find the median Q₂

The median is the middle value of the data arranged in ascending order.

8, 9, 9, 9, 10, 11, 13, 15, 17, 18, 22

↑ Q₂

The upper quartile is the middle value of the data to the right of the median

13, 15, 17, 18, 22

↑ Q₃

The lower quartile is the middle value of the data to the left of the median

8, 9, 9, 9, 10

↑ Q₁

IQR = Q₃ - Q₁ = 17 - 9 = 8