Statistics & Probability

Geometric Distribution

P(first success on trial k).

Formula

Formula
P = (1−p)k−1 · p

Variables

SymbolDefinitionType & rangeUnitsRole
p success probability real number (ℝ) input
k trial number integer (ℤ) input

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Givenprob p = 0.2, k = 3
Result0.128
Example 2
Givenprob p = 0.5, k = 1
Result0.5