Standard deviation measures the typical distance of a value from the mean.
Standard deviation
σ = √(Σ(xᵢ − x̄)²/n)
In a normal distribution, ~68% of data lies within 1 SD of the mean, ~95% within 2 SDs.
Standard deviation measures the typical distance of a value from the mean.
In a normal distribution, ~68% of data lies within 1 SD of the mean, ~95% within 2 SDs.