Definition

An acronym for Inter-Quartile Range, or the value that describes the middle 50% of a frequency distribution. IQR = Q3 - Q1, where Q3 = third quartile (the point with 75% of the data below it) and Q1 = first quartile (the point with 25% of the data below it).

Application

The IQR is graphically represented in a Box plot.

See Also

Q1, Q2, Q3, Boxplot