POISSON

This function returns the Poisson distribution.

Syntax

POISSON(x, mean, cumulative)

This function has these arguments:

Argument	Description
x	[Required] Number of events. Provide an integer, or the value is truncated. The number must be greater than zero
mean	[Required] Expected numeric value. The number must be greater than zero
cumulative	[Required] Set to TRUE to return the cumulative Poisson probability that the number of random events occurring is between zero and x inclusive. Set to FALSE to return the Poisson probability mass function that the number of events occurring is exactly x

The cumulative Poisson probability is calculated as follows:

The Poisson probability mass function is calculated as follows:

where x is the number of events ( x argument), and mu is the mean ( mean argument).

POISSON(A3,B4,TRUE)

POISSON(R1C2,3,FALSE)

POISSON(7,4,TRUE) gives the result 0.948866384

POISSON(7,4,FALSE) gives the result 0.059540363