# Interquartile Range (IQR)

**Interquartile range (IQR)** is the middle half of a collection of numbers that are ordered from lowest to highest.

To find the interquartile range of a collection:

- Find the median of the collection
- Find the median of lower and upper half of the collection, leaving out the median number(s)
- Subtract the lower half's median from the upper half's median. The difference is the $IQR$

## Resources

## Broader Topics Related to Interquartile Range (IQR)

### Median

How to calculate the median of a collection of numbers

### Statistics

The analysis of numerical data