Sample space: 2 dice

Data on prison sentences

Empirical probabilities from prison sentence data

Data on endangered species

Empirical compound probabilities from endangered species data

Addition rule for mutually exclusive events

General additional rule (events not mutually exclusive – we don’t want to double-count the overlap, so we subtract it off once

Example of non-mutually exclusive events using the endangered species data: A = reptiles, B = U.S., so A&B = reptiles in the U.S.

Classical probability example of addition rule with mutually exclusive events (a) and non-mutually exclusive events (c)

Finishing off example from last slide

A similar example

… and finishing that one off.