Probabilities for normal, binomial and Poisson distributions.
Computed with standard statistical methods in your browser.
Normal uses the cumulative normal curve; binomial uses the exact mass function with log-factorials for stability; Poisson uses e^−λ λ^k ÷ k!. We report exact and cumulative probabilities.
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For continuous, roughly bell-shaped data described by a mean and standard deviation.
The probability of k successes in n independent trials each with success probability p.
For counts of rare events over a fixed interval, defined by an average rate λ.
The cumulative probability of getting that value or fewer.
Yes — we use log-factorials to stay accurate for large n.