POISSON ( x , mean , cumulative-flag )
Description: Computes the Poisson distribution.
Mathematical Formula:
For cumulative-flag = FALSE:
For cumulative-flag = TRUE:
Arguments:
|
Name |
Type |
Description |
|
number |
The number of events, truncated to an integer. | |
|
mean |
number |
The expected numeric value. |
|
cumulative-flag |
logical |
Determines the form of the function. If TRUE, POISSON returns the cumulative Poisson probability that the number of random events occurring will be between zero and x, inclusive; if FALSE, it returns the Poisson probability mass function that the number of events occurring will be exactly x. |
Return Type and Value: number – The Poisson distribution.
However, if
• x < 0, #NUM! is returned.
• mean ≤ 0, #NUM! is returned.
[Example:
POISSON(2,5,TRUE) results in 0.124652019
POISSON(2,5,FALSE) results in 0.084224337
end example]