Question

Calculate the interquartile range of the data set below: 30, 6, 1, 22, 19, 7, 8​

Answer 1

IQR = 13

Explanation:

first step is to find the median of the data set.

rearrange the data into ascending order. Then the median is the middle value.

1 , 6 , 7 , 8 , 12 , 19 , 30 ← in ascending order

↑ middle

then median = 8

the interquartile range (IQR) is calculated as

IQR = Q₃ - Q₁ ( Q₃ is the upper quartile and Q₁ the lower quartile )

Q₃ is the middle value of the data to the right of the median

12 , 19 , 30

↑ middle

then Q₃ = 19

Q₁ is the middle value of the data to the left of the median

1 , 6 , 7

↑ middle

then Q₃ = 6

IQR = 19 - 6 = 13