Statistics & Probability

Binomial Probability

P(X = k) for n trials with success prob p.

Formula

Formula
C(n,k) pk (1−p)n−k

Variables

SymbolDefinitionType & rangeUnitsRole
n trials integer (ℤ) input
k successes integer (ℤ) input
p success probability real number (ℝ) input

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Giventrials n = 10, successes k = 3, prob p = 0.5
Result0.1171875
Example 2
Giventrials n = 20, successes k = 5, prob p = 0.25
Result0.2023311519