Question 1

The following scatter plot indicates that ___.

Accepted Answer

A) a log x transform may be useful 
B) a y2 transform may be useful 
C) a x2 transform may be useful 
D) no transform is needed 
E) a 1/x transform may be useful 
A) a log x transform may be useful 
B) a y2 transform may be useful 
C) a x2 transform may be useful 
D) no transform is needed 
E) a 1/x transform may be useful

Question 2

Abby Ross, a market specialist at the market research firm of Saez, Gann, and Spitz, is analyzing household budget data collected by her firm.Abby's dependent variable is monthly household expenditures on groceries (in $'s), and her independent variables are annual household income (in $1,000's)and household neighbourhood (0 = suburban, 1 = rural).Regression analysis of the data yielded the following table:   Abby's model is ___.

Accepted Answer

A) y = 19.68247 + 10.01176 x1 + 1.965934 x2 
B) y = 1.965934 + 9.940612 x1 + 6.416667 x2 
C) y = 10.01176 + 0.174564 x1 + 7.655776 x2 
D) y = 19.68247 - 1.735272 x1 + 49.12456 x2 
E) y = 19.68247 + 1.735272 x1 + 49.12456 x2 
A) y = 19.68247 + 10.01176 x1 + 1.965934 x2 
B) y = 1.965934 + 9.940612 x1 + 6.416667 x2 
C) y = 10.01176 + 0.174564 x1 + 7.655776 x2 
D) y = 19.68247 - 1.735272 x1 + 49.12456 x2 
E) y = 19.68247 + 1.735272 x1 + 49.12456 x2

Question 3

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

Accepted Answer

A) x1 and x2 
B) x1 and x5 
C) x3 and x4 
D) x2 and x5 
E) x3 and x5 
A) x1 and x2 
B) x1 and x5 
C) x3 and x4 
D) x2 and x5 
E) x3 and x5

Question 4

The regression model is called a quadratic model.

Accepted Answer

A) True 
 B)False

Question 5

If a qualitative variable has c categories, then c dummy variables must be included in the regression model, one for each category.

Accepted Answer

A) True 
 B)False

Question 6

If a qualitative variable has c categories, then only (c - 1)dummy variables must be included in the regression model.

Accepted Answer

A) True 
 B)False

Question 7

If the effect of an independent variable (e.g., humidity)on a dependent variable (e.g., hardness)is affected by different ranges of values for a second independent variable (e.g., temperature), the two independent variables are said to interact.

Accepted Answer

A) True 
 B)False

Question 8

A multiple regression analysis produced the following tables:     The regression equation for this analysis is ___.

Accepted Answer

A) y = 707.9144 + 2.903307 x1 + 11.91297 x12 
B) y = 707.9144 + 435.1183 x1 + 1.626947 x12 
C) y = 435.1183 + 81.62802 x1 + 3.806211 x12 
D) y = 1.626947 + 0.035568 x1 + 3.129878 x12 
E) y = 1.626947 + 0.035568 x1 - 3.129878 x12 
A) y = 707.9144 + 2.903307 x1 + 11.91297 x12 
B) y = 707.9144 + 435.1183 x1 + 1.626947 x12 
C) y = 435.1183 + 81.62802 x1 + 3.806211 x12 
D) y = 1.626947 + 0.035568 x1 + 3.129878 x12 
E) y = 1.626947 + 0.035568 x1 - 3.129878 x12

Question 9

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

Accepted Answer

A) x1 and x2 
B) x1 and x4 
C) x4 and x5 
D) x4 and x3 
E) x5 and y 
A) x1 and x2 
B) x1 and x4 
C) x4 and x5 
D) x4 and x3 
E) x5 and y

Question 10

An appropriate method to identify multicollinearity in a regression model is to ___.

Accepted Answer

A) examine a residual plot 
B) examine the ANOVA table 
C) examine a correlation matrix 
D) examine the partial regression coefficients 
E) examine the R2 of the regression model 
A) examine a residual plot 
B) examine the ANOVA table 
C) examine a correlation matrix 
D) examine the partial regression coefficients 
E) examine the R2 of the regression model

Question 11

After a transformation of the y-variable values into log y, and performing a regression analysis produced the following tables:     For x1= 10, the predicted value of y is ___.

Accepted Answer

A) 155.79 
B) 1.25 
C) 2.42 
D) 189.06 
E) 18.90 
A) 155.79 
B) 1.25 
C) 2.42 
D) 189.06 
E) 18.90

Question 12

A useful technique in controlling multicollinearity involves the ___.

Accepted Answer

A) use of variance inflation factors 
B) use of the backward elimination procedure 
C) use of the forward elimination procedure 
D) use of the forward selection procedure 
E) use of all possible regressions 
A) use of variance inflation factors 
B) use of the backward elimination procedure 
C) use of the forward elimination procedure 
D) use of the forward selection procedure 
E) use of all possible regressions

Question 13

Which of the following iterative search procedures for model building in a multiple regression analysis adds variables to the model as it proceeds, but does not re-evaluate the contribution of previously entered variables?

Accepted Answer

A) backward elimination 
B) stepwise regression 
C) forward selection 
D) all possible regressions 
E) forward elimination 
A) backward elimination 
B) stepwise regression 
C) forward selection 
D) all possible regressions 
E) forward elimination

Question 14

Alan Ho, a market analyst for Clear Sound Inc., is analyzing sales of heavy metal CD's.Alan's dependent variable is annual heavy metal CD sales (in $1,000,000's), and his independent variables are teenage population (in 1,000's)and type of sales district (0 = urban, 1 = rural).Regression analysis of the data yielded the following tables:   Alan's model is ___.

Accepted Answer

A) y = 1.7 + 0.384212 x1 + 4.424638 x2 + 0.00166 x3 
B) y = 1.7 + 0.04 x1 + 1.5666667 x2 
C) y = 0.384212 + 0.014029 x1 + 0.20518 x2 
D) y = 4.424638 + 2.851146 x1 - 7.63558 x2 
E) y = 1.7 + 0.04 x1 - 1.5666667 x2 
A) y = 1.7 + 0.384212 x1 + 4.424638 x2 + 0.00166 x3 
B) y = 1.7 + 0.04 x1 + 1.5666667 x2 
C) y = 0.384212 + 0.014029 x1 + 0.20518 x2 
D) y = 4.424638 + 2.851146 x1 - 7.63558 x2 
E) y = 1.7 + 0.04 x1 - 1.5666667 x2

Question 15

A qualitative variable which represents categories such as geographical territories or job classifications may be included in a regression model by using indicator or dummy variables.

Accepted Answer

A) True 
 B)False

The following scatter plot indicates that ___.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

The regression model is called a quadratic model.

If a qualitative variable has c categories, then c dummy variables must be included in the regression model, one for each category.

If a qualitative variable has c categories, then only (c - 1)dummy variables must be included in the regression model.

If the effect of an independent variable (e.g., humidity)on a dependent variable (e.g., hardness)is affected by different ranges of values for a second independent variable (e.g., temperature), the two independent variables are said to interact.

A multiple regression analysis produced the following tables: The regression equation for this analysis is ___.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

An appropriate method to identify multicollinearity in a regression model is to ___.

After a transformation of the y-variable values into log y, and performing a regression analysis produced the following tables: For x₁= 10, the predicted value of y is ___.

A useful technique in controlling multicollinearity involves the ___.

Which of the following iterative search procedures for model building in a multiple regression analysis adds variables to the model as it proceeds, but does not re-evaluate the contribution of previously entered variables?

A qualitative variable which represents categories such as geographical territories or job classifications may be included in a regression model by using indicator or dummy variables.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Exam 14: Building Multiple Regression Models

The following scatter plot indicates that ___.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

The regression model is called a quadratic model.

If a qualitative variable has c categories, then c dummy variables must be included in the regression model, one for each category.

If a qualitative variable has c categories, then only (c - 1)dummy variables must be included in the regression model.

If the effect of an independent variable (e.g., humidity)on a dependent variable (e.g., hardness)is affected by different ranges of values for a second independent variable (e.g., temperature), the two independent variables are said to interact.

A multiple regression analysis produced the following tables: The regression equation for this analysis is ___.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___.

An appropriate method to identify multicollinearity in a regression model is to ___.

After a transformation of the y-variable values into log y, and performing a regression analysis produced the following tables: For x1= 10, the predicted value of y is ___.

A useful technique in controlling multicollinearity involves the ___.

Which of the following iterative search procedures for model building in a multiple regression analysis adds variables to the model as it proceeds, but does not re-evaluate the contribution of previously entered variables?

A qualitative variable which represents categories such as geographical territories or job classifications may be included in a regression model by using indicator or dummy variables.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

After a transformation of the y-variable values into log y, and performing a regression analysis produced the following tables: For x₁= 10, the predicted value of y is ___.