[[Estimator]]
# Sample skewness
Let $\{ X_{j} \}_{j=1}^n$ be a sample of [[Independence of random variables|independent and identically distributed]] [[Real random variable|real random variables]] with [[Expectation|mean]] $\mu$ and [[Standard deviation|variance]] $\sigma^2$.
The **sample skewness** is #m/def/prob 
$$
\begin{align*}
 \frac{\frac{1}{n}\sum_{j=1}^n(X_{j}- \overline{X}_{n})^3}{S^3_{n}}
\end{align*}
$$
where $S_{n}^2$ is the [[Sample variance]].
This estimates the [[Skewness]] of a sample.

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#state/tidy | #lang/en | #SemBr