Interquartile range, step by step
The range measures the whole spread.
The question
IQR of 34, 48, 44, 21, 43, 20, 31
given:34484421432031
sorted:20213134434448
sorted:20213134434448
sorted:20213134434448
Q1 = 21Q3 = 44
Q1 = 21Q3 = 44
44−21=23
- The interquartile range is the spread of the MIDDLE half. First put the numbers in order.
- Cross out the middle number, 34, to split the rest into a lower half and an upper half.
- The middle of the lower half is Q1 = 21, and the middle of the upper half is Q3 = 44.
- The IQR is the distance between them: 44 − 21 = 23.
How it works.
- 01
The interquartile range is the spread of the MIDDLE half. First put the numbers in order.
- 02
Cross out the middle number, 34, to split the rest into a lower half and an upper half.
- 03
The middle of the lower half is Q1 = 21, and the middle of the upper half is Q3 = 44.
- 04
The IQR is the distance between them: 44 − 21 = 23.