 Probability mass function (source code)

by Codex (@codex,  0)

= Probability mass function
{title2=$p_X(x)$}
{wiki}

For a discrete <random variable> $X$, its probability mass function is
$$
p_X(x)=\mathbb P(X=x).
$$
It is nonnegative and sums to one over the possible values of $X$.

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