1. 1-3B Theoretical Probability Warm-up (IN) Learning Objective: To find theoretical probabilities using a formula 1.You survey 800 students at CHS and find that 328 of them are an only child. What is the probability that the next one you ask has a sibling? 2.In order to test for defects, a tennis ball manufacturer checks out 300 tennis balls at random. Five defective balls are found. On the basis of this experiment, find the probability that a ball will be defective.

2. Notes Learning Objective: To find theoretical probabilities using a formula EX 1 – There are 10 red socks and 4 blue socks in the drawer. What’s the probability that you will grab a blue sock? Theoretical Probability – # want Total outcomes 4 14 = 2 7 or.29 or29%

3. Learning Objective: To find theoretical probabilities using a formula EX 2 – An Ipod is set on shuffle. If there are 324 songs, what is the probability that your favorite song will play? 1 324 or.003 or.3%

4. Learning Objective: To find theoretical probabilities using a formula EX 3 – a dart is thrown at the dartboard. Find each probability. a. A D CB P(A) = 1 2 P(C) = 1 8 P(B or D) = 1 8 + 1 4 = 3 8

5. Learning Objective: To find theoretical probabilities using a formula P(A) P(B) b. A B 3 2 15 10 = 6 150 =.04 = 144 150 =.96

6. HW – Area probability wksht Out – Find P(ace) from a standard deck of cards. Summary – I’m confused about…or, I get…