Interquartile Range

Divide a set of data into two groups (high and low) of equal size at the statistical median if there is an even number of data points, or two groups consisting of points on either side of the statistical median itself plus the statistical median if there is an odd number of data points. Find the statistical medians of the low and high groups, denoting these first and third quartiles by Q_1 and Q_3. The interquartile range is then defined by


See also

Box-and-Whisker Plot, H-Spread, Hinge, Quartile, Statistical Median

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Gonick, L. and Smith, W. The Cartoon Guide to Statistics. New York: Harper Perennial, pp. 20-21, 1993.

Referenced on Wolfram|Alpha

Interquartile Range

Cite this as:

Weisstein, Eric W. "Interquartile Range." From MathWorld--A Wolfram Web Resource.

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