Skewness in terms of Non-Central Moments

Theorem
Let $X$ be a random variable with mean $\mu$ and standard deviation $\sigma$.

Then the skewness of $X$, $\gamma_1$ is given by:


 * $\gamma_1 = \dfrac {\expect {X^3} - 3 \mu \sigma^2 - \mu^3} {\sigma^3}$