Answer:
To find the interquartile range, first arrange the values in the data set in ascending order:
0, 5, 5, 10, 10, 10, 15, 15, 15, 20, 20, 20, 25, 25, 30.
Because there are 15 values in the data set, the first quartile is the 4th value, which is 10, and the third quartile is the 12th value, which is 20.
interquartile range
=
third quartile – first quartile
=
20 – 10
=
10
The interquartile range of Warren's data is 10.