<Dl> <Dd> σ n 2 = Q n n (\ displaystyle \ sigma _ (n) ^ (2) = (\ frac (Q_ (n)) (n))) </Dd> </Dl> <Dd> σ n 2 = Q n n (\ displaystyle \ sigma _ (n) ^ (2) = (\ frac (Q_ (n)) (n))) </Dd> <P> When the values x are weighted with unequal weights w, the power sums s, s, s are each computed as: </P> <Dl> <Dd> s j = ∑ k = 1 N w k x k j . (\ displaystyle \ s_ (j) = \ sum _ (k = 1) ^ (N) (w_ (k) x_ (k) ^ (j)). \,) </Dd> </Dl>

Standard deviation measures how much variation exists in a distribution of data