# POISSON.DISTDAX Function (Statistical)

Returns the Poisson distribution. A common application of the Poisson distribution is predicting the number of events over a specific time, such as the number of cars arriving at a toll plaza in 1 minute.

## Syntax

POISSON.DIST ( <X>, <Mean>, <Cumulative> )
Parameter Attributes Description
X

The number of events.

Mean

The expected numeric value.

Cumulative

A logical value that determines the form of the probability distribution returned. If cumulative is TRUE, POISSON.DIST 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 values

Scalar A single decimal value.

Returns the Poisson distribution.

## Remarks

If x is not an integer, it is rounded.

If x or mean is nonnumeric, POISSON.DIST returns the #VALUE! error value.

If x < 0, POISSON.DIST returns the #NUM! error value. If mean < 0, POISSON.DIST returns the #NUM! error value.

Last update: Dec 17, 2019     » Show contributors

Contributors: Alberto Ferrari, Marco Russo

MSDN documentation: https://docs.microsoft.com/en-us/dax/poisson-dist-function-dax

DAX Conventions
• Use [measure] and never use table[measure]
• Use table[column] and never use [column]
• Space before ‘(‘ and ‘)’ and any operand and operator
• Space before an in-line argument
• Definitions in the first row, including the assignment
• Use ‘=’ to define calculated columns / tables
• Use ‘:=’ to define measures
Context Transition

This function performs a Context Transition if called in a Row Context. Click to read more.

Row Context

This expression is executed in a Row Context. Click to read more.

Iterator

Not recommended

The use of this function is not recommended. See Remarks and Related functions for alternatives.

Not recommended

The use of this parameter is not recommended.

Deprecated

This function is deprecated. Jump to the Alternatives section to see the function to use.

Deprecated

This parameter is deprecated and its use is not recommended.

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