# Problems and Exercises

All Problems are from the book Seeing Through Statistics by Jessica Utts unless otherwise marked.
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Notation: 	n	manditory problem

(n)	helper problem

{n} 	thought problem

Bracketed problems do not have to be turned in.

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

Homework 10

13	1	postage stamps
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

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
14	computer sales drop
15	presidential salary
16	adjusting the dow jones for inflation

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