A specialization of the Negative Binomial distribution, where the experiment is stopped after the first success.
Applies to problems where an experiment is done until a fixed number of successes ( n ) in a certain number of trials ( k ) occur. These types of experiments are called negative binomial experiments. The negative binomial random variable is k.
Applies to processes with small constant probabilities. Is a good approximation to a binomial distribution for large n and small p.