Hypergeometric distribution is the probability distribution related with the sampling without replacement from the population of finite size. If the population comprises of r elements of one kind and N - r of another kind, then the probability of finding x elements of the ?rst kind m when a random sample of the size n drawn is given by the following formula
The mean of the x is nr/N and its variance cab be given as When N is big and n is small compared to N, the hypergeometric distribution can be estimated by the usage of binomial distribution.