# Documentation/How Tos/Calc: NEGBINOMDIST function

From Apache OpenOffice Wiki

## NEGBINOMDIST

Calculates probabilities for a negative binomial distribution.

### Syntax:

**NEGBINOMDIST(x; r; p)**

- For independent trials each with a probability
of success,**p**returns the probability that there will be exactly**NEGBINOMDIST**failures before there have been**x**successes. The formula used is:**r**

### Example:

**NEGBINOMDIST(1; 1; 0.5)**

- returns 0.25 (25%), the probability that heads will come up exactly once before tails has come up when tossing a coin.