Question 1

The best model is a statistically significant model with a high r-square and few variables.

Accepted Answer

A) True 
 B)False

Question 2

Which of these statements about multiple regression is best?

Accepted Answer

A) The p-value for the F-test may not be interpreted the same with multiple regression models as they are with simple linear models. 
B) The multiple regression model includes several dependent variables. 
C) The multiple regression model includes several intercept terms. 
D) The multiple regression model includes multiple slope coefficients. 
A) The p-value for the F-test may not be interpreted the same with multiple regression models as they are with simple linear models. 
B) The multiple regression model includes several dependent variables. 
C) The multiple regression model includes several intercept terms. 
D) The multiple regression model includes multiple slope coefficients.

Question 3

Describe a residual plot.

Accepted Answer

A residual plot is a plot of t

Question 4

The mean square error (MSE)is

Accepted Answer

A) denoted by s. 
B) denoted by k. 
C) the SSE divided by the number of observations. 
D) the SSE divided by the degrees of freedom. 
A) denoted by s. 
B) denoted by k. 
C) the SSE divided by the number of observations. 
D) the SSE divided by the degrees of freedom.

Question 5

If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns.

Accepted Answer

A) True 
 B)False

Question 6

Explain what r2 is.

Accepted Answer

It is a value between 0 and +1

Question 7

Discuss the relationship between r2 and adjusted r2.

Accepted Answer

The value of r² can never decrease when m

Question 8

Which of the following statements is true about r2?

Accepted Answer

A) It is also called the coefficient of correlation. 
B) It is also called the coefficient of determination. 
C) It represents the percent of variation in X that is explained by Y. 
D) It represents the percent of variation in the error that is explained by Y. 
A) It is also called the coefficient of correlation. 
B) It is also called the coefficient of determination. 
C) It represents the percent of variation in X that is explained by Y. 
D) It represents the percent of variation in the error that is explained by Y.

Question 9

The coefficients of each independent variable in a multiple regression model represent slopes.

Accepted Answer

A) True 
 B)False

Question 10

Which of these statements is best?

Accepted Answer

A) If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns. 
B) The error standard deviation is estimated by MSE. 
C) Often, a plot of the residuals will highlight any glaring violations of the assumptions. 
D) The standard error of the estimate is also called the variance of the regression. 
A) If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns. 
B) The error standard deviation is estimated by MSE. 
C) Often, a plot of the residuals will highlight any glaring violations of the assumptions. 
D) The standard error of the estimate is also called the variance of the regression.

Question 11

An automated process to systematically add or delete independent variables from a regression model is called

Accepted Answer

A) nonlinear regression. 
B) linear regression. 
C) residual analysis. 
D) stepwise regression. 
A) nonlinear regression. 
B) linear regression. 
C) residual analysis. 
D) stepwise regression.

Question 12

A large international sales organization has collected data on the number of employees and the annual gross sales during the last 7 years.
   (a)Develop a scatter diagram.
(b)Determine the correlation coefficient.
(c)Determine the coefficient of determination.
(d)Determine the least squares trend line.
(e)Determine the predicted value of sales for 2100 employees.

Accepted Answer

(a) @#IMG-DLM& (b).937 (c).878

Question 13

Which of the following equalities is correct?

Accepted Answer

A) SST = SSR + SSE 
B) SSR = SST + SSE 
C) SSE = SSR + SST 
D) SST = SSC + SSR 
A) SST = SSR + SSE 
B) SSR = SST + SSE 
C) SSE = SSR + SST 
D) SST = SSC + SSR

Question 14

The value of r2 can never decrease when more variables are added to the model.

Accepted Answer

A) True 
 B)False

Question 15

The random error in a regression equation

Accepted Answer

A) is the predicted error. 
B) includes both positive and negative terms. 
C) will sum to a large positive number. 
D) is used to estimate the accuracy of the slope. 
A) is the predicted error. 
B) includes both positive and negative terms. 
C) will sum to a large positive number. 
D) is used to estimate the accuracy of the slope.

Question 16

A large school district is reevaluating its teachers' salaries.They have decided to use regression analysis to predict mean teacher salaries at each elementary school.The researcher uses years of experience to predict salary.The raw data is given in the table below.The resulting equation was:
Y = 19389.21 + 1330.12X, where Y = salary and X = years of experience
   (a)Develop a scatter diagram.
(b)What is the correlation coefficient?
(c)What is the coefficient of determination?

Accepted Answer

(a) @#IMG-DLM& (b).9

Question 17

A healthcare executive is using regression to predict total revenues.She has decided to include both patient length of stay and insurance type in her model.Insurance type can be grouped into the following categories: Medicare, Medicaid, Managed Care, Self-Pay, and Charity.Which of the following is true?

Accepted Answer

A) Insurance type will be represented in the regression model by five binary variables. 
B) Insurance type will be represented in the regression model by six dummy variables. 
C) Insurance type will be represented in the regression model by five dummy variables. 
D) Insurance type will be represented in the regression model by four binary variables. 
A) Insurance type will be represented in the regression model by five binary variables. 
B) Insurance type will be represented in the regression model by six dummy variables. 
C) Insurance type will be represented in the regression model by five dummy variables. 
D) Insurance type will be represented in the regression model by four binary variables.

Question 18

Which of the following is not a common pitfall of regression?

Accepted Answer

A) If the assumptions are not met, the statistical tests may not be valid. 
B) Nonlinear relationships cannot be incorporated. 
C) Two variables may be highly correlated to one another but one is not causing the other to change. 
D) Concluding that a statistically significant relationship implies practical value. 
A) If the assumptions are not met, the statistical tests may not be valid. 
B) Nonlinear relationships cannot be incorporated. 
C) Two variables may be highly correlated to one another but one is not causing the other to change. 
D) Concluding that a statistically significant relationship implies practical value.

Question 19

Errors are also called residuals.

Accepted Answer

A) True 
 B)False

Question 20

A study was done to determine the relationship between GPA and starting salaries for college graduates.The data is shown in the table below:
   Use model building to determine the best fit based on highest adjusted r2.

Accepted Answer

Y = 227,141.10 - 144385X₁ + 272

The best model is a statistically significant model with a high r-square and few variables.

Which of these statements about multiple regression is best?

Describe a residual plot.

The mean square error (MSE)is

If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns.

Explain what r² is.

Discuss the relationship between r² and adjusted r².

Which of the following statements is true about r²?

The coefficients of each independent variable in a multiple regression model represent slopes.

Which of these statements is best?

An automated process to systematically add or delete independent variables from a regression model is called

Which of the following equalities is correct?

The value of r² can never decrease when more variables are added to the model.

The random error in a regression equation

Which of the following is not a common pitfall of regression?

Errors are also called residuals.

A study was done to determine the relationship between GPA and starting salaries for college graduates.The data is shown in the table below: Use model building to determine the best fit based on highest adjusted r2.

Introduction to Quantitative Analysis

Probability Concepts and Applications

Decision Analysis

Forecasting

Inventory Control Models

Linear Programming Models: Graphical and Computer Methods

Linear Programming Applications

Transportation, Assignment, and Network Models

Integer Programming, Goal Programming, and Nonlinear Programming

Project Management

Waiting Lines and Queuing Theory Models

Simulation Modeling

Markov Analysis

Statistical Quality Control

Analytic Hierarchy Process

Dynamic Programming

Decision Theory and the Normal Distribution

Game Theory

Mathematical Tools: Determinants and Matrices

Calculus-Based Optimization

Linear Programming: The Simplex Method

Transportation, Assignment, and Network Algorithms

Filters

Exam 4: Regression Models

The best model is a statistically significant model with a high r-square and few variables.

Which of these statements about multiple regression is best?

Describe a residual plot.

The mean square error (MSE)is

If the assumptions of regression have been met, errors plotted against the independent variable will typically show patterns.

Explain what r2 is.

Discuss the relationship between r2 and adjusted r2.

Which of the following statements is true about r2?

The coefficients of each independent variable in a multiple regression model represent slopes.

Which of these statements is best?

An automated process to systematically add or delete independent variables from a regression model is called

Which of the following equalities is correct?

The value of r2 can never decrease when more variables are added to the model.

The random error in a regression equation

Which of the following is not a common pitfall of regression?

Errors are also called residuals.

A study was done to determine the relationship between GPA and starting salaries for college graduates.The data is shown in the table below: Use model building to determine the best fit based on highest adjusted r2.

Introduction to Quantitative Analysis

Probability Concepts and Applications

Decision Analysis

Forecasting

Inventory Control Models

Linear Programming Models: Graphical and Computer Methods

Linear Programming Applications

Transportation, Assignment, and Network Models

Integer Programming, Goal Programming, and Nonlinear Programming

Project Management

Waiting Lines and Queuing Theory Models

Simulation Modeling

Markov Analysis

Statistical Quality Control

Analytic Hierarchy Process

Dynamic Programming

Decision Theory and the Normal Distribution

Game Theory

Mathematical Tools: Determinants and Matrices

Calculus-Based Optimization

Linear Programming: The Simplex Method

Transportation, Assignment, and Network Algorithms

Filters

Explain what r² is.

Discuss the relationship between r² and adjusted r².

Which of the following statements is true about r²?

The value of r² can never decrease when more variables are added to the model.