PROBNEGB Function

PROBNEGB Function

Returns the probability from a negative binomial distribution

Category: Probability

See: 'CDF Function' on page 418

Syntax

PROBNEGB ( p,n,m )

Arguments

p

• is a numeric probability of success parameter.

• Range: ‰ p ‰ 1

n

• is an integer number of successes parameter.

• Range: n ‰ 1

m

• is a positive integer random variable, the number of failures.

• Range: m ‰

Details

The PROBNEGB function returns the probability that an observation from a negative binomial distribution, with probability of success p and number of successes n , is less than or equal to m .

To compute the probability that an observation is equal to a given value m , compute the difference of two probabilities from the negative binomial distribution for m and m -1.

Examples

SAS Statements	Results
x=probnegb(0.5,2,1);	0.5