Statistics & Probability
Intermediate

Interquartile Range

Spread of the middle 50% of the data.

Formula

IQR=Q3Q1IQR = Q_3 - Q_1

Variables

Q_3Third quartile
Q_1First quartile

Example

Robust measure of spread

Did You Know?

The interquartile range ignores the extreme 25% at each end, making it a robust measure used in box plots.