# Documentation/Calc Functions/NEGBINOM.DIST

NEGBINOM.DIST

## Category:

Statistical Analysis

## Summary:

Calculate a probability mass function or a cumulative distribution function for the negative binomial distribution for the given data about the number of failures, successes, and the probability of success for each attempt.

## Syntax:

NEGBINOM.DIST(X; R; SP; Cumulative)

## Returns:

Returns a real number which is either a probability mass function or a cumulative distribution function for the negative binomial distribution with the count of the unsuccessful test as X, successful tests as R, and the probability of success as SP.

## Arguments:

X is an integer value or a reference to the cell containing that value which represents the value returned for unsuccessful tests.

R is an integer value or a reference to the cell containing that value which represents the value returned for successful tests.

SP is a real number between 0 and 1 or a reference to the cell containing that value which is the probability of the success of an attempt.

Cumulative specifies whether to calculate the probability mass function (FALSE or 0) or the cumulative distribution function (any other value).

• If R is less than 1 or X is less than 0 then the function returns an error value.
• If R or X are non-integer values then the function takes the floor of their value, i.e. they are truncated to integers.
• If SP is greater than 1 or less than 0, then the function returns an error value.

• The formula for NEGBINOM.DIST is:

If Cumulative is FALSE() and (X + R - 1)>=0 then the probability mass function value

If Cumulative is TRUE() and (X + R - 1)>=0 then the cumulative distribution function value

where x = X, r = R and p = SP

• For more details on the negative binomial distribution, visit Wikipedia.

## Examples:

Formula Description Returns
=NEGBINOM.DIST(5;12;0.5;0) The function calculates the probability mass function for the negative binomial distribution for the given arguments. 0.0333251953125
=NEGBINOM.DIST(4;12;0.5;1) The function calculates the cumulative distribution function for the negative binomial distribution for the given arguments. 0.038406372070313
=NEGBINOM.DIST(5;0.9;0.5;0) The function returns an error value since R is less than 1. Err:502

NEGBINOMDIST

BINOM.INV

BINOMDIST

B

None

NEGBINOM.DIST