Definition 1.7.2. Skewness.
For population data, the Skewness of \(x_1, x_2, ..., x_n\) is given by
\begin{equation*}
\gamma_1 = \frac{1}{\sigma^3} \frac{\sum_{k=1}^n ( x_k-\mu )^3}{n}.
\end{equation*}
For sample data, the Skewness of \(x_1, x_2, ..., x_n\) is given by
\begin{equation*}
g_1 = \frac{1}{s^3} \frac{\sum_{k=1}^n ( x_k-\overline{x} )^3}{n-1}.
\end{equation*}