# POISSON

### Definition of POISSON

Returns the value of the Poisson distribution function (or Poisson cumulative distribution function) for a specified value and mean.

### Sample Usage

`POISSON(2.4,1,FALSE)`

`POISSON(A2,A3,TRUE)`

### Syntax

`POISSON(x, mean, cumulative)`

`x`

- The input to the Poisson distribution function.`mean`

- The mean (mu) of the Poisson distribution function.`cumulative`

- Whether to use the Poisson cumulative distribution function rather than the distribution function..

### Notes

The Poisson distribution function is typically used to calculate the number of 'arrivals' or 'events' over a period of time, such as the number of network packets or login attempts given some mean.

If

`cumulative`

is`TRUE`

then`POISSON`

returns the probability of`x`

or fewer events, otherwise the probability of exactly`x`

events.

### See Also

`WEIBULL`

: Returns the value of the Weibull distribution function (or Weibull cumulative distribution function) for a specified shape and scale.

`NORMSINV`

: Returns the value of the inverse standard normal distribution function for a specified value.

`NORMSDIST`

: Returns the value of the standard normal cumulative distribution function for a specified value.

`NORMINV`

: Returns the value of the inverse normal distribution function for a specified value, mean, and standard deviation.

`NORMDIST`

: Returns the value of the normal distribution function (or normal cumulative distribution function) for a specified value, mean, and standard deviation.

`NEGBINOMDIST`

: Calculates the probability of drawing a certain number of failures before a certain number of successes given a probability of success in independent trials.

`LOGNORMDIST`

: Returns the value of the log-normal cumulative distribution with given mean and standard deviation at a specified value.

`LOGINV`

: Returns the value of the inverse log-normal cumulative distribution with given mean and standard deviation at a specified value.

`EXPONDIST`

: Returns the value of the exponential distribution function with a specified lambda at a specified value.

`BINOMDIST`

: Calculates the probability of drawing a certain number of successes (or a maximum number of successes) in a certain number of tries given a population of a certain size containing a certain number of successes, with replacement of draws.

### In order to use the POISSON formula, start with your edited Excellentable

### Then type in the POISSON Formula in area you would like to display the outcome:

### Type in the complete POISSON formula for a cell as shown below:

### Excellentable will generate the outcome when hitting enter.

arrivals, x