POISSON.DIST (X, Mean, IsCumulative) POISSON.DIST (X; Mean; IsCumulative)
X
Number Number
The number of events.
Mean
Number Number
The expected number.
IsCumulative
Logical Logical
TRUE to return the probability that a value is at most the value of the X parameter (the cumulative distribution function). FALSE to return the probability of exactly that value (the probability mass function).
Returns
Number Number
A value for a Poisson distribution.
Returns a probability for the Poisson distribution. The Poisson distribution models the number of events occurring in a fixed interval of time or space, given a known average rate.
Examples
POISSON.DIST (3, 5, FALSE)
POISSON.DIST (3; 5; FALSE)
Returns roughly 0.1404, the probability that exactly 3 events occur in a period where the expected number of events is 5.
POISSON.DIST (3, 5, TRUE)
POISSON.DIST (3; 5; TRUE)
Returns roughly 0.2650, the probability that 3 or fewer events occur in a period where the expected number of events is 5.