AP Statistics / Mr. Hansen 4/4/2003

Name: _________________________ Initials to certify honor system compliance: ______

Quiz on Chapters 11 and 12 (Honor System)

Part I.	Time limit should have been 10 minutes for Part I, but students were allowed about 20 minutes on 4/4/2003. Limit yourself to 20 minutes, please. If you wish, you may use your formula sheets (8 pages in Barron’s book, but no other pages).
	A double-blind study performed on male physicians age 40 and older examined the effects of taking aspirin on a regular schedule. The 22,071 subjects were divided into two groups: 11,037 were selected at random to take aspirin, and the others took a placebo. Three outcomes of interest had the following counts in the experimental and control groups:
			Aspirin takers	Placebo takers
	I.	Heart attacks (fatal)	10	26
	II.	Heart attacks (nonfatal)	129	213
	III.	Strokes	119	98
1.	For which outcome(s) (I, II, and/or III) is there a statistically significant difference between the aspirin and placebo groups at the a = .05 level? No work needed, but compute a P-value for each.
2.	Check the assumptions needed in the problem.
3.	Briefly state why we do not use the formula for s.e., but rather , in the 3 problems shown above.
4.	Compute s.e. for outcome I (fatal heart attack outcome).
5.	State what you found in #4. “I found the s.e. of _______________________ _______________________________________ .”

Part II.	Time limit for this section: 13 minutes.
	Turn to p. 648 of your textbook without looking at any other pages. Set an accurate timer for 13 minutes. Then read the problem and begin. Show the entire “skeleton” of the approach to part (a) and fill in as many of the details as time permits. Also do parts (b) and (c).