Returns the negative binomial distribution, the probability that there will be the specified number of failures before the last success, with the specified probability of a success.
| Name | Type | Description |
| arg1 | number | The number of failures. |
| arg2 | number | The threshold number of successes. |
| arg3 | number | The probability of a success; a number between 0 and 1. |
| arg4 | boolean | A logical value (true or false) that determines the function form. If it is true, the function returns the cumulative distribution function. If it is false, the function returns the probability density function. |