Editing Log-normal distribution (section)

==== Method of moments ====
When the individual values <math>x_1, x_2, \ldots, x_n</math> are not available, but the sample's mean <math>\bar x</math> and [[standard deviation]] ''s'' is, then the [[Method of moments (statistics)|method of moments]] can be used. The corresponding parameters are determined by the following formulas, obtained from solving the equations for the expectation <math>\operatorname{E}[X]</math> and variance <math>\operatorname{Var}[X]</math> for <math>\mu</math> and <math>\sigma</math>:<ref>Henry (https://math.stackexchange.com/users/6460/henry), Method of moments estimator for lognormal distribution, URL (version: 2022-01-12): https://math.stackexchange.com/q/4355343</ref>
<math display="block"> \begin{align}
\mu &= \ln \frac{ \bar x} {\sqrt{1+\widehat\sigma^2/\bar x^2} } , \\[1ex]
\sigma^2 &= \ln\left(1 + {\widehat\sigma^2} / \bar x^2 \right).
\end{align}</math>