# HP Prime for All

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BINOMIAL_CDF(n, p, k, [k2])

Cumulative binomial distribution function.
Returns the probability of k or fewer successes out of n trials, with a probability of success, p for each trial.
Note that n and k are integers with k≤n.
With the optional fourth arguments k2, returns the cumulative probability for the two k-values; that is, the probability of between k and k2 successes.

BINOMIAL_CDF(20, 0.5, 6) returns 0.05765914917
BINOMIAL_CDF(20, 0.5, 6, 12) returns 0.847717285156