LESSON 5.7 Probability

Socrative (12/9) You choose a card out of a standard deck. P(diamond)? You roll 2 fair dice. P(5 or 7)? The chance it will rain tomorrow is 37%. What is the probability of its complement? A plush Minnie Mouse doll is on sale for $ The original price was $ What is the discount rate? Please write your answer to the nearest whole percent.

A compound event is made up of one or more separate events. To find the probability of a compound event, you need to know if the events are independent or dependent. Events are independent events if the occurrence of one event DOES NOT affect the probability of the other. Events are dependent events if the occurrence of one event DOES affect the probability of the other.

Practice 1. P(roll even #, spin odd) = 2. P(roll a 2 or 3, spin a 7) = 3. P(roll a 7, spin an even #) = 4. Are these events independent or dependent?

Solving Probabilities: P( a AND b) : P(A) * P(B given A) P(a OR b) : P(A) + P(B) Relative Frequency: the probability of an event that actually occurred- written as a percent or fraction. Theoretical Probability: Probability of events that SHOULD occur mathematically.

Probability: Uncopyrightable P(vowel): P(vowel, then immediately pulling out another vowel): P(consonant): P(vowel or consonant): P(A, not putting it back, then U):

10 socks are in a drawer: 3 red, 4 blue, 3 white. What is the probability that you will pick a red sock and then pick a blue sock ? What is the probability that you will pick a red sock, return it to the drawer, then pick a blue sock?

A coin and a die P(heads, even #): P(tails, # less than 3): P(tails, 5 or 6):

You Try… OutcomeABCD Probability Use the table to find the probability of each event. 1. P(C) 2. P(not B) 3. P(A or D) 4. P(A and C) Remember: Or means to add the probabilities together. Not means add all of the other probabilities together. And means to multiply the probabilities.