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Interquartile Range
IQR

The difference between the first quartile and third quartile of a set of data. This is one way to describe the spread of a set of data.

Example showing five-number summary for data {2,5,6,9,12}: min=2, Q1=3.5, median=6, Q3=10.5, max=12; IQR=10.5−3.5=7

See also

Five-number summary, median, outlier

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