Poisson Distribution

A Poisson distribution is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space if these events occur with a known constant mean rate and independently of the time since the last event. The probability mass function (PMF) is given by:

$$P(k; \lambda) = \frac{\lambda^k e^{-\lambda}}{k!}$$

Mean ($\lambda$):

Poisson Distribution

Key Probabilities