## Inter-Quartile Range for ungrouped data

The difference between the third quartile $Q_3$ and the first quartile $Q_1$ is called Inter-quartile range.

## Formula

The inter-quartile range is given by

### $IQR=Q_3-Q_1$

where

• $Q_1$ is the first quartile of the data
• $Q_3$ is the third quartile of the data