## 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

### $E(X) =\dfrac{Mn}{N}$.

## Variance of Hypergeometric Distribution

The variance of an hypergeometric random variable is