Answer:
IQR = 8
Step-by-step 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
