Mean Deviation

Updated 15 Sep 2026

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What it is
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  the average of the absolute differences between each data point and the mean — a measure of dispersion
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formula (ungrouped)
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  $SR = \dfrac{\sum_{i=1}^{n} |x_i - \bar{x}|}{n}$
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formula (grouped)
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  $SR = \dfrac{\sum f_i |x_i - \bar{x}|}{\sum f_i}$ , where $x_i$ is each class's midpoint * related
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Related
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  Measures of Dispersion
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  Variance

Linked references 1