Interquartile Range

Topics: Statistics - Quantile

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(definition)

The interquartile range (or IQR for short, RIC in Spanish) is defined as:

$$\mathrm{IQR}=q(0.75)-q(0.25)$$

…where $q(0.75)$ and $q(0.25)$ are the variable’s third and first quartiles, respectively.

In other words, the IQR is the distance between a variable’s first and third quartiles. The IQR is widely used in box plots.