Distributions Pack Calculator (Binomial / Poisson / Student's t / Chi-square)

Run PMF/PDF, CDF, quantile, and exact CI calculations in one place, with a transparent How it’s calculated log, canvas visualizations, CSV, LaTeX, and shareable URLs.

Regularized beta/gamma routines keep the CDFs stable, Acklam’s normal approximation plus Newton steps invert the quantiles, and exact Clopper–Pearson / chi-square intervals help you justify estimates in class.

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Inputs & Modes

Parameters

Result

How it’s calculated

    Visualization

    Discrete distributions render as bars with highlighted tails; continuous ones display the PDF curve plus shaded regions or quantile markers.

    Teacher notes

    FAQ

    How are CDFs and quantiles computed?

    Binomial CDFs use regularized incomplete beta, Poisson and chi-square rely on regularized gamma, and Student’s t maps to beta functions combined with Newton or bisection for robust inversion.

    What can I do with the exact intervals?

    The Clopper–Pearson interval for p and the chi-square based interval for λ quantify uncertainty exactly, so you can document precision requirements in labs or assessments.