Re: standard deviation calculation and evaluation - Weitzman eqn?
I always use the version where you divide by n-1. and not by in as in GTOT. I believe my version is the unbiased, variance minimizing estimator, instead of the maximum likelyhood one.
Dividing by n-1 gives the unbiased estimate of the variance, but taking the square root of this does not give the unbiased estimate of the standard deviation, that is a more complicated formula. Dividing by n+1 minimizes the mean squared error of the variance estimate.
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