1. Section 9-3 Probability

2. Probability of an Event if E is an event in a sample space, S, of equally likely outcomes, then the probability of the event E is:

3. Probability the probability of an event must be between 0 and 1, inclusive the sum of the probabilities of all the outcomes in S is 1 P(empty set) = 0 the probability of an event E is the sum of the probabilities of all the outcomes contained in E (“or” problems)

4. Multiplication Principle of Probability very similar to MPC which is used for counting, we’ll call it MPP if A and B are independent, then: if A and B are not independent, then:

5. Probability Tools Venn diagrams can be very useful in working on probability problems that involve percentages or groups that have common outcomes Tree diagrams are useful for problems involving the MPP and events that are not independent

6. Conditional Probability this is an adjustment of the MPP formula introduced earlier If the event B depends on the event A, then:

7. Binomial Distribution used for an experiment with n independent repetitions of an experiment with two outcomes, called “success” and “failure” P(success) = p and P(failure) = q let r be the number of successes out of n attempts, its probability is: