3.3 Two Basic Rules of Probability
Chapter Objectives
- Understand and use the terminology of probability
- Determine whether two events are mutually exclusive and whether two events are independent
- Calculate probabilities using the addition rules and multiplication rules
- Construct and interpret contingency tables
- Construct and interpret Venn diagrams
- Construct and interpret tree diagrams
Assignment
- All vocabulary (see Key Terms for definitions)
- 3.3 Homework 81–99 odds
- Read the next section in the book
Basic Rules of probability
The multiplication rule for AND events.
\[\begin{align} P(A \text{ and } B) &= P(A|B)\cdot P(B) \\ \end{align}\]The addition rule for OR events.
\[\begin{align} P(A \text{ or } B) &= P(A) + P(B) - P(A \text{ and } B) \end{align}\]