PHP マニュアル: Probability mass function of the binomial distribution

説明

float stats_dens_pmf_binomial(float $x, float $n, float $pi)

Returns the probability mass at x, where the random variable follows the binomial distribution of which the number of trials is n and the success rate is pi.

パラメータ

x: The value at which the probability mass is calculated
n: The number of trials of the distribution
pi: The success rate of the distribution

戻り値

The probability mass at x or false for failure.