What is the iqr (inter quartile range) for the data set? 27, 4, 54, 78, 27, 48, 79, 64, 5, 6, 41, 71?

There are 12 data in this set and they can be properly arranged in increasing order as,

4, 5, 6, 27, 27, 41, 48, 54, 64, 71, 78, 79

Dividing them into quartiles:

Q1 : 4, 5, 6 with the middle term equal to 5

Q2 : 27,27, 41 with the middle term equal to 27

Q3: 41, 48, 54 with the middle term equal to 48

Q4: 71, 78, 79 with the middle term equal to 78

The interquatile range is the difference between the middle terms of Q3 and Q1.

IQR = 48 - 5 = 43