Probability Distributions Cheat Sheet
By Dr. Iris Vaughan, Mathematics Editor·Published 1 November 2025·Last reviewed 10 February 2026
Binomial, normal, Poisson, geometric, and hypergeometric distributions — with parameter definitions, mean/variance formulas, and when each applies.
Key Formulas
Binomial(n,p): P(X=k)=C(n,k)pᵏ(1−p)ⁿ⁻ᵏ
Normal(μ,σ²): continuous, symmetric
Poisson(λ): P(X=k)=e⁻λλᵏ/k!
Geometric(p): P(X=k)=(1−p)ᵏ⁻¹p
Download Printable PDF
Get this cheat sheet formatted for A4 or US Letter printing — no ads, clean layout, exam-ready. $9 via Gumroad.
View in Shop