Category:Definitions/Skewness

This category contains definitions related to Skewness.
Related results can be found in Category:Skewness.

Skewness is a measure of the asymmetry of a probability distribution about its mean.

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

Then the skewness of $X$, usually denoted $\gamma_1$, is defined as:

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

where $\expect X$ denotes the expectation of $X$.