excercise10 (2) - Exercise Questions Chapter 10 10.1...

Exercise Questions: Chapter 10
10.1
Understanding a linear regression model. Consider a linear regression model with μ
y
=
40.5 - 2.5 x and standard deviation = 2.0.
(a) What is the slope of the population regression line?
(b) Explain clearly what this slope says about the change in the mean of y for a change in
x .
(c) What is the subpopulation mean when x = 10?
(d) Between what 2 values would approximately 95% of the observed responses, y , fall
when x = 10?
10.7 What’s wrong? For each of the following, explain what is wrong and why.
(a) The parameters of the simple linear regression model are b
0
, b
1
, and s .
(b) To test H
0
: b
1
= 0, use a t test.
(c) For a particular value of the explanatory variable x , the confidence interval for the
mean response will be wider than the prediction interval for a future observation.
10.13 Beer and blood alcohol. How well does the number of beers a student drinks
predict his or her blood alcohol content? Sixteen student volunteers at Ohio State
University drank a randomly assigned number of 12-ounce cans of beer. Thirty minutes
later, a police officer measured their blood alcohol content (BAC). Here are the data:
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