What is the interquartile range of this data 0 5 10 15 20

The interquartile range (IQR) is 15.

To find the IQR, you must:

1) Find the median

2) Split the data set in two at the median.

3) Find the medians from both the groups you made in Step 2

4) Label the smaller one Quartile 1 and the larger one Quartile 3 (Hint: The median is Quartile 2)

5) Subtract: Quartile 3 - Quartile 1