Services
Discover
Homeschooling
Ask a Question
Log in
Sign up
Filters
Done
Question type:
Essay
Multiple Choice
Short Answer
True False
Matching
Topic
Statistics
Study Set
Business Statistics in Practice Study Set 1
Quiz 12: Multiple Regression and Model Building
Path 4
Access For Free
Share
All types
Filters
Study Flashcards
Practice Exam
Learn
Question 181
Essay
A multiple linear regression analysis involving 45 observations resulted in the following least squares prediction equation:
y
^
=
.
408
+
1.3387
x
1
+
2.1
x
2
\hat { y } = .408 + 1.3387 x _ { 1 } + 2.1 x _ { 2 }
y
^
=
.408
+
1.3387
x
1
+
2.1
x
2
. The SSE for the above model is 49. Addition of two other independent variables to the model,resulted in the following multiple linear regression equation:
y
^
=
1.2
+
3
x
1
+
12
x
2
+
4
x
3
+
8
x
4
\hat { y } = 1.2 + 3 x _ { 1 } + 12 x _ { 2 } + 4 x _ { 3 } + 8 x _ { 4 }
y
^
=
1.2
+
3
x
1
+
12
x
2
+
4
x
3
+
8
x
4
. The latter model's SSE is 40. -Determine the degrees of freedom regression (explained variation),degrees of freedom error (unexplained variation),and total degrees of freedom for the model with two independent variables.
Question 182
Essay
The analyst performing the study wants to determine if at least one of the two new independent variables makes a significant contribution to the multiple regression model.State the appropriate null and alternative hypotheses.
Question 183
Essay
Use the following correlation matrix and determine the best multiple regression prediction equation that has no significant multicollinearity.
Question 184
Essay
A multiple linear regression analysis involving 45 observations resulted in the following least squares prediction equation:
y
^
=
.
408
+
1.3387
x
1
+
2.1
x
2
\hat { y } = .408 + 1.3387 x _ { 1 } + 2.1 x _ { 2 }
y
^
=
.408
+
1.3387
x
1
+
2.1
x
2
. The SSE for the above model is 49. Addition of two other independent variables to the model,resulted in the following multiple linear regression equation:
y
^
=
1.2
+
3
x
1
+
12
x
2
+
4
x
3
+
8
x
4
\hat { y } = 1.2 + 3 x _ { 1 } + 12 x _ { 2 } + 4 x _ { 3 } + 8 x _ { 4 }
y
^
=
1.2
+
3
x
1
+
12
x
2
+
4
x
3
+
8
x
4
. The latter model's SSE is 40. -Determine the degrees of freedom regression (explained variation),degrees of freedom error (unexplained variation),and total degrees of freedom for the latter model (the model with four independent variables).
Question 185
Essay
Consider the following partial computer output for a multiple regression model.
Predictor
Coefficient
Standard Deviation
Constant
41.225
6.380
X
1
1.081
1.353
X
2
−
18.404
4.547
\begin{array} { l c c } \text { Predictor } & \text { Coefficient } & \text { Standard Deviation } \\\text { Constant } & 41.225 & 6.380 \\\mathrm { X } _ { 1 } & 1.081 & 1.353 \\\mathrm { X } _ { 2 } & - 18.404 & 4.547\end{array}
Predictor
Constant
X
1
X
2
Coefficient
41.225
1.081
−
18.404
Standard Deviation
6.380
1.353
4.547
Analysis of Variance
Source
D
F
‾
S
S
‾
Regression
2
2270.11
Error (residual)
26
3585.75
\begin{array} { l r c } \text { Source } & \underline { \mathrm { DF } } & \underline { \mathrm { SS } } \\\text { Regression } & 2 & 2270.11 \\\text { Error (residual) } & 26 & 3585.75\end{array}
Source
Regression
Error (residual)
DF
2
26
SS
2270.11
3585.75
-What is the total sum of squares (total variation)?
Question 186
Essay
The management of a professional baseball team is in the process of determining the budget for next year.A major component of future revenue is attendance at the home games.In order to predict attendance at home games,the team's statistician has used a multiple regression model with dummy variables.The model is of the form: y = β
0
+ β
1
x
1
+ β
2
x
2
+ β
3
x
3
+ ε where: Y = attendance at a home game x1= current power rating of the team on a scale from 0 to 100 before the game. x2and x3are dummy variables,and they are defined below. x2= 1,if weekend x2= 0,otherwise x3= 1,if weather is favourable x3= 0,otherwise After collecting the data based on 30 games from last year and implementing the above stated multiple regression model,the team statistician obtained the following least squares multiple regression equation:
y
^
=
−
1050
+
250
x
1
+
2200
x
2
+
5400
x
3
\hat { y } = - 1050 + 250 x _ { 1 } + 2200 x _ { 2 } + 5400 x _ { 3 }
y
^
=
−
1050
+
250
x
1
+
2200
x
2
+
5400
x
3
The multiple regression compute output also indicated the following:
s
b
1
=
800
,
s
b
2
=
1000
,
s
b
3
=
1850
s _ { b _ { 1 } } = 800 , s _ { b _ { 2 } } = 1000 , s _ { b _ { 3 } } = 1850
s
b
1
=
800
,
s
b
2
=
1000
,
s
b
3
=
1850
-Assume that the overall model is useful in predicting the game attendance and the team statistician wants to know if the mean attendance is higher on the weekends as compared to the weekdays.At alpha = .05,test to determine if the attendance is higher on weekend home games.
Question 187
Essay
Consider the following partial computer output for a multiple regression model.
Predictor
Coefficient
Standard Deviation
Constant
41.225
6.380
X
1
1.081
1.353
X
2
−
18.404
4.547
\begin{array} { l c c } \text { Predictor } & \text { Coefficient } & \text { Standard Deviation } \\\text { Constant } & 41.225 & 6.380 \\\mathrm { X } _ { 1 } & 1.081 & 1.353 \\\mathrm { X } _ { 2 } & - 18.404 & 4.547\end{array}
Predictor
Constant
X
1
X
2
Coefficient
41.225
1.081
−
18.404
Standard Deviation
6.380
1.353
4.547
Analysis of Variance
Source
D
F
‾
S
S
‾
Regression
2
2270.11
Error (residual)
26
3585.75
\begin{array} { l r c } \text { Source } & \underline { \mathrm { DF } } & \underline { \mathrm { SS } } \\\text { Regression } & 2 & 2270.11 \\\text { Error (residual) } & 26 & 3585.75\end{array}
Source
Regression
Error (residual)
DF
2
26
SS
2270.11
3585.75
-What is the mean square error?
Question 188
Essay
A county has four major hospitals: 1)Regional Memorial;2)General;3)Charity;and 4)City.A multiple regression model is used to compare the time spent in the hospital after a heart by-pass surgery among the four hospitals.The response variable is the amount of time spent in the hospital (in days),the quantitative independent variables include the age of the patient,cholesterol level of the patient,and blood pressure of the patient.Define the dummy variables so that all other hospitals are compared to the City hospital (base).
Question 189
Essay
Consider the following partial computer output for a multiple regression model.
Predictor
Coefficient
Standard Deviation
Constant
41.225
6.380
X
1
1.081
1.353
X
2
−
18.404
4.547
\begin{array} { l c c } \text { Predictor } & \text { Coefficient } & \text { Standard Deviation } \\\text { Constant } & 41.225 & 6.380 \\\mathrm { X } _ { 1 } & 1.081 & 1.353 \\\mathrm { X } _ { 2 } & - 18.404 & 4.547\end{array}
Predictor
Constant
X
1
X
2
Coefficient
41.225
1.081
−
18.404
Standard Deviation
6.380
1.353
4.547
Analysis of Variance
Source
D
F
‾
S
S
‾
Regression
2
2270.11
Error (residual)
26
3585.75
\begin{array} { l r c } \text { Source } & \underline { \mathrm { DF } } & \underline { \mathrm { SS } } \\\text { Regression } & 2 & 2270.11 \\\text { Error (residual) } & 26 & 3585.75\end{array}
Source
Regression
Error (residual)
DF
2
26
SS
2270.11
3585.75
-Calculate R
2
.
Question 190
Essay
The management of a professional baseball team is in the process of determining the budget for next year.A major component of future revenue is attendance at the home games.In order to predict attendance at home games,the team's statistician has used a multiple regression model with dummy variables.The model is of the form: y = β
0
+ β
1
x
1
+ β
2
x
2
+ β
3
x
3
+ ε where: Y = attendance at a home game x1= current power rating of the team on a scale from 0 to 100 before the game. x2and x3are dummy variables,and they are defined below. x2= 1,if weekend x2= 0,otherwise x3= 1,if weather is favourable x3= 0,otherwise After collecting the data based on 30 games from last year and implementing the above stated multiple regression model,the team statistician obtained the following least squares multiple regression equation:
y
^
=
−
1050
+
250
x
1
+
2200
x
2
+
5400
x
3
\hat { y } = - 1050 + 250 x _ { 1 } + 2200 x _ { 2 } + 5400 x _ { 3 }
y
^
=
−
1050
+
250
x
1
+
2200
x
2
+
5400
x
3
The multiple regression compute output also indicated the following:
s
b
1
=
800
,
s
b
2
=
1000
,
s
b
3
=
1850
s _ { b _ { 1 } } = 800 , s _ { b _ { 2 } } = 1000 , s _ { b _ { 3 } } = 1850
s
b
1
=
800
,
s
b
2
=
1000
,
s
b
3
=
1850
-Assume that the overall model is useful in predicting the game attendance.Assume today is Wednesday morning and the weather forecast indicates sunny,excellent weather conditions for the rest of the day.Later today,there is a home baseball game for this team.Assume that the current power rating of the team is 85 and predict the attendance for today's game.
Question 191
Essay
A multiple regression model with four independent variables consists of 29 observations.The multiple coefficient of determination is R
2
= .80 and the standard error is s = 2.0.Complete the analysis of variance table for this model and test the overall model for significance.
Question 192
Essay
A multiple regression model with 3 independent variables and 16 observations produced the following results: SSE = 15 and R
2
= 2/3.Complete the analysis of variance table and calculate the F statistic.