POISSON.DIST Function Explained
The POISSON.DIST Function in Microsoft Excel calculates the probability of a given number of events occurring in a fixed interval of time or space when the rate of events is known. It takes three arguments: the number of events (x), the expected number of events (mean), and a logical value (cumulative) that determines whether the function returns the probability of the exact number of events or the probability of the exact number of events or fewer.
POISSON.DIST Function Syntax
POISSON.DIST(x, mean, cumulative)
- x: The number of successes that are counted.
- mean: The expected numeric value of the distribution.
- cumulative: A logical value that determines the form of the function. If cumulative is TRUE, POISSON.DIST returns the cumulative Poisson probability that the number of random events occurring will be between zero and x; if FALSE, it returns the Poisson probability mass function that the number of events occurring will be equal to x.