Math W50
How Do They Know My Opinion?
Interim 2000

Problems and Exercises

All Problems are from the book Seeing Through Statistics by Jessica Utts unless otherwise marked.

Notation: 	n	manditory problem


		(n)	helper problem

		{n} 	thought problem 

		[n]	ungraded problem

Bracketed problems do not have to be turned in.


Chap	Prob	Description/Notes
====	====	=================

Homework 10 

13	1	postage stamps
	2	inflation by decade
	4	weighting of items in the CPI
	[5,8]	problems with CPI
	6	medical care index
	7	birthday money
	[10]	other price indexes
	11	updating the CPI
	[12]	percentage increase vs. index value
	13	bracket creep
	14	COLAs
	[15]	leading economic indicators

Supplemental problems:

  1. Suppose a certain medical condition affects 3 percent of the 
	population.  You sample 400 Calvin College graduates and find
	that 20 of them have the condition.  Is this difference (between
	the general population and Calvin alumni) statistically significant?
	Explain.

  2. Your friend claims to have ESP and be able to tell the suit (clubs, 
	diamonds, hearts, or spades) of a card you are looking at without
	actually seeing it.  You don't believe it, so you conduct an 
	experiment in which you repeatedly shuffle a deck of cards, 
	draw one card, and look at it while your friend tries to guess 
	the suit.  You did this 100 times and your friend was correct 32 
	of those 100 times.  "See, I got more than 25%," your friend boasts.  
	Should you be impressed?  How likely would it be to get 32 (or more) 
	of 100 correct by simply guessing?

  3. If you have a choice between a 1-tailed Z-test and a 2-tailed Z-test,
	which will have the larger p-value?  Why?


Homework 11 14 1-2 what's the trend? seasonal component? 6 displaying homocides 7 rates per 100,000 13 seasonal adjustments 14 computer sales drop 15 presidential salary 16 adjusting the dow jones for inflation

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This page maintained by:
Randall Pruim
Department of Mathematics and Statistics
Calvin College
rpruim@calvin.edu

Last Modified: Thursday, 11-Jan-2001 16:02:15 EST