# Mike Love’s blog

## Standard deviation

Posted in statistics by mikelove on November 1, 2011

I should really memorize this to baffle someone in the future:

$E(s^2) = \sigma^2$
$E(s) = \sigma [ 1 - \frac{1}{4n} - \frac{7}{32n^2} - \frac{19}{128n^3} + O(n^{-4}) ]$

unbiased estimation of standard deviation