Chapter 9 Homework Due 11/16
1. In forward stepwise regression, what advantage is there to using a small
What advantage is there in using a large
-to-enter value?
-to-enter value?
2. An engineer has stated: Reduction of the number of explanatory variabl
Chapter 4 Homework: Due Oct 5,
2016
1. You are reviewing a paper and the author presents the results of a simple linear regression. They
give a 95% confidence interval over
0 and another 95% confidence interval around
1 .
They then state that our entire
Chapter 1 Homework - Due 9/14
1. Consider a regression of the form
Y i= 0 + 1 X i+ i .
a. Using the rules for expectation operators, show that
b. Using the rules for variance operators, show that
E cfw_ Y i = 0 + 1 X
2 cfw_ Y i = 2
0=0 ? What would the
Chapter 3 Homework - Due 9/28
1. You are reviewing a paper for a journal where the authors describe a linear regression they fit
predicting externalizing behavior from scores on the Beck Depression Inventory. They describe a
significant, positive, linear
Christal Davis
Chapter 7/8 Homework Due Nov
9th
1. State the number of degrees of freedom that are associated with each of the following extra
sums of squares:
SSR ( X 1 X 2)
a.
df = 1
SSR ( X 2| X 1 , X 3 )
b.
df = 1
SSR ( X 1 , X 2X 3 , X 4)
c.
df = 2
S
Chapter 6 Homework Due 11/2
1. A student stated Adding predictor variables to a regression model can never reduce
R
2
, so
we should include all available predictor variables in the model. What do you say to this
student?
Based on the equation for the coe
Christal Davis
Chapter 2 Homework Due 9/21
1. A researcher collects data on the hours worked per week and happiness on 100 employees
at a company. She checked the assumptions of normal-error regression and found it to be
an appropriate analysis for the da