The interquartile range of the data set will be 30.
<u><em>Explanation</em></u>
Given data set: { 40, 48, 62, 60, 62, 40, 25, 50, 20, 30, 55 }
First we will rearrange the data in numeric order. So...
{ 20, 25, <u><em>30</em></u>, 40, 40, 48, 50, 55, <u><em>60</em></u>, 62, 62 }
Here the middle value in the set is 48. So, the median is 48 and it is diving the whole set into two different data sets. The median of the first set is 30 and median of the second set is 60.
That means, Lower quartile(Q₁) = 30 and Upper quartile(Q₃) = 60
So, the interquartile range of the data set: IQR= Q₃ - Q₁ = 60 - 30 = 30
