If one knows ΣX , N , and ΣX ², one can calculate both the variance and the standard deviation. It is not necessary to know the mean itself.

Question

Quizplus · Accepted Answer

This is true. The formula for variance is Var(X) = Σ(X^2) / N - (ΣX / N)^2 and the formula for standard deviation is SD(X) = √[Σ(X^2) / N - (ΣX / N)^2]. Both formulas involve ΣX, N, and Σ(X^2), so the mean is not required to calculate the variance or standard deviation.

If One Knows ΣX , N , and ΣX 2

If One Knows ΣX , N , and ΣX ²