Measures of Variability: Interquartile Range (IQR)

Measures of Variability: Interquartile Range (IQR)
Introduction

The interquartile range, or IQR, measures the spread of the middle 50 percent of a data set. It is calculated as the difference between the upper quartile and the lowe...

A group of students timed how long it took them to run one lap around the track. They wanted to compare their running times.

Here, 90 seconds is much larger than the others. This value is called an outlier. Outliers can make the data seem more spread out than most of the values actually are. To better understand the spread of the running ...