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Discrete Probability Distributions

Interactive visualization of six fundamental discrete distributions

Discrete Uniform

Equal probability for finite outcomes

Explanation

A discrete uniform distribution assigns equal probability to each value in a finite range. The probability mass function is P(X=k)=1ba+1P(X = k) = \frac{1}{b - a + 1} for akba \leq k \leq b. The expected value is E[X]=a+b2E[X] = \frac{a + b}{2}, and the variance is Var(X)=n2112\text{Var}(X) = \frac{n^2 - 1}{12}, where n=ba+1n = b - a + 1. Common examples include rolling a fair die, selecting a random card from a deck, or generating a random number from a finite range.