Statistics & Probability

Complement Rule

Probability that an event does not occur.

P(Eᶜ)=1−P(E)

Variables

Eᶜ
not E

Example

P(E)=.3 → complement=.7

How to use this formula

Identify the known values, keep units consistent, substitute the values into the formula, and calculate carefully. Then check whether the result is reasonable for the original problem.