1. HOMEWORK QUESTIONS?

2. 5.2 TWO-WAY TABLES

3. PROBABILITY MODELS A probability model describes chance behavior by listing the possible outcomes in the sample space and giving the probability that each outcome occurs. Example: Color of MarbleRedGreenBlue Probability0.40.10.5

4. BASIC RULES OF PROBABILITY

5. ARE THESE MUTUALLY EXCLUSIVE? Turning left and turning right Drawing a king and drawing an ace Tossing a coin Drawing a king and drawing an ace Turning your head and scratching your foot

6. ADDITION RULE FOR MUTUALLY EXCLUSIVE If A and B are mutually exclusive, P(A or B) = P(A) + P(B) For example, find the probability that you pull an ace or a king out of a deck of cards.

7. ANOTHER EXAMPLE In a game of soccer, the probability of scoring no goals (event A) is 20%. The probability of scoring exactly 1 goal (event B) is 15%. Find P(A and B) Find P(A or B)

8. TWO-WAY TABLES Students in a college statistics class wanted to find out how common it is for young adults to have their ears pierced. They recorded data on two variables – gender and whether the student had a pierced ear – for all 178 people in the class. Here is the two-way table describing their results. Suppose we choose a student at random. Find the probability that the student: a) has pierced ears b) is a male with pierced ears c) is a male or has pierced ears GenderYesNoTotal Male197190 Female84488 Total10375178 Define events! A – is male B – has pierced ears

9. ONE MORE EXAMPLE Let A be the event that the person is a female and B be the event that the person is underweight. Try to answer these on your own: 1.P(A) = 2.P(B) = 3.P(A or B) = 4.P(A and B) =

10. HOMEWORK Pg 308 (39-50) Check Mr. Suk’s website for extra help videos! They will really help you along the way!