Negative Binomial Probability Distribution Calculator

The Negative Binomial Probability Distribution Calculator finds the exact and cumulative probabilities. Input the number of successful trials, r, the probability of a successful trial, p, and the number of the trials, k. The calculator outputs the exact and all cumulative probabilities.

Probability Calculator

Negative Binomial Distribution: X ~ NB(r,p)

Number of successes (r):

Probability of success (p):

Number of trials (k):

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Understanding the Negative Binomial Distribution

The negative binomial distribution is a discrete probability distribution that is used to find the probability that the rth successful trial occurs on the kth trial, the probability equation is given:

Negative Binomial Probability Equation:

$P(X = k) = \binom{k-1}{r-1} \cdot p^{r} \cdot (1-p)^{k-r}$