## Hypergeometric Distribution

The probability mass function of Hypergeometric distribution is

$$\begin{equation*} P(X=x)=\frac{\binom{M}{x}\binom{N-M}{n-x}}{\binom{N}{n}},\;\; x=0,1,2,\cdots, n. \end{equation*}$$

## Mean of Hypergeometric Distribution

The expected value of hypergeometric random variable is

## Variance of Hypergeometric Distribution

The variance of an hypergeometric random variable is