1. Warm-Up  Grab a half sheet and start working on it!  It says QUIZ at the top, so NO TALKING!

2. Section 11.2

3. Finding Expected Counts  Expected count for French wine bought when there was no music playing: WineNo MusicFrench Music Italian Music Total French303930 99 Italian11119 31 Other4335 113 Total847584243

4. Does background music influence what customers buy? WineNo MusicFrench Music Italian Music Total French99 Italian31 Other113 Total847584243

5. Chi-Squared test for Homogeneity  The null hypothesis is that the distribution of this categorical variable is the same for all the populations or treatments.  Remember…this is when we are imposing treatments!  What would the hypotheses be for this problem?

6. Still have to check conditions!  For this problem…  Random –  Large sample size – each expected count in your table still has to be at least 5.  Independent –

7. Find chi-squared for the sum of the nine terms

8. Using your calculator  Go to STAT and look at the chi-squared test…it uses matrices!  Let’s test the last problem!

9. Chi-Squared test for association/independence

10. Do angry people have more heart disease?  A study followed a random sample of 8474 people with normal blood pressure (and no heart disease) for about 4 years. Each person took and Anger Test to measure how prone a person is to sudden anger. Researchers also recorded whether each person developed coronary heart disease (CHD) below. Low AngerModerate AngerHigh AngerTotal CHD5311027190 No CHD305746216068284 Total311047316338474

11.  State:  Plan:

12.  Do:  Conclude:

13. Choose the right test!  Are men and women equally likely to suffer lingering fear from watching scary movies as children? Researched asked a sample of 117 college students to write narratives of their exposure to scary movies before the age of 13. Fright Symptoms? MaleFemaleTotal Yes72936 No315081 Total3879117

14. How to tell?  If it is an associations test – does this variable have anything to do with this other variable – one sample  If it is a homogeneity test – multiple samples(experiments count as multiple samples) – does the distribution of each sample match?

15. Homework  Pg 724 (29-33, 35-41, 44, 50, 53-58)