Changes

(where <math>\bar X =  {\sum_n X_n  \over N}</math> is the [[sample mean]]).

(where <math>\bar X =  {\sum_n X_n  \over N}</math> is the [[sample mean]]).

which is the formula for a [[point estimate]] of the true standard deviation from a sample size of ''n''.  As such this estimator itself has a variance which, as the formula indicates, decreases as the sample size increases.

which is the formula for a [[point estimate]] of the true standard deviation from a sample size of ''n''.  As such this [[statistical estimator]] itself has a variance which, as the formula indicates, decreases as the sample size increases.