σ
Standard Deviation Calculator
How spread out your numbers are around their mean, for a sample or a whole population.
Result…
How it's calculated
Sample: s = √( Σ(x − x̄)² ÷ (n − 1) ) Population: σ = √( Σ(x − μ)² ÷ n )
The standard deviation is the typical distance of a value from the mean, in the same units as the data. Use "sample" when your numbers are a sample drawn from a bigger group (the usual case); it divides by n − 1 to correct the bias. Use "population" only when you have every member of the group.
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