Negative Binomial Distribution Function

JavaScript

      Enter Negative Binomial Distribution Arguments

            x-value: 
 Number of failures: 
Success Probability:

Negative Binomial Probability :

If independent trials with probability p of success at each trial
are performed until the rth failure occurs, then the distribution
of the observed number of successes follows the negative binomial
distribution, NB(r,p), with probability mass function,

f(x | r,p) = C_r+x-1,x, (1-p)^r p^x for x = 0,1,2,...

where C_r+x-1,x, is the number of combinations of r+x-1 things
taken x at a time. The important special case, r=1, is the
geometric distribution, NB(1,p). For example, F(0 | 1,.5)=.5