Question

How do you find the range and interquartile range of 9, 10, 12, 13, 10, 14, 8, 10, 12, 6, 8, 11, 12, 12, 9, 11, 10, 15, 10, 8, 8, 12, 10, 14, 10, 9, 7, 5, 11, 15, 8, 9, 17, 12, 12, 13, 7, 14, 6, 17, 11, 15, 10, 13, 9, 7, 12, 13, 10, 12?

Answer 1

To find the range of this set of data you would take the biggest number and subtract it from the smallest number (max-min).

To find the interquartile range (IQR) for this problem would be harder since there are so many numbers, you can still find the IQR butfirst you need to know about Quartile 1, 2, and 3.

Lets start with Quartile 2, that is the median of your box and whisker plot, the middle number of your data is your Q2. Q1 is the middle number of your first half of data (re-read it again if it sounds confusing). Your Q3 is the middle number of your second half of data.

To find the IQR you would take your Q3 and subtract it from your Q1 (Q3-Q1).