7th Grade · Statistics & Probability

Probability

7.SP.C.5

Definition

A number between 0 and 1 that measures how likely an event is to occur. P = favorable outcomes ÷ total equally likely outcomes.

Examples

  • P(rolling a 4 on a die) = 1/6 ≈ 0.167.
  • P = 0 means impossible; P = 1 means certain.

Key rule

Probability is always between 0 and 1.

Memory hook

How likely, on a scale from impossible to certain.