negative binomial distribution

The Negative Binomial Distribution is a statistical model used to describe the number of trials needed to achieve a certain number of successes in a sequence of independent experiments. For example, if you’re flipping a coin and want to know how many flips it takes to get, say, three "heads," the distribution helps predict that. It accounts for the random nature of success and failure, making it useful in various fields, like quality control, ecology, and epidemiology, where you want to model the occurrence of events until a defined goal is reached.