Question 1

A variable should be added to the model regardless of the impact (increase or decrease)on the adjusted r2 value.

Accepted Answer

A) True 
 B)False

Question 2

One purpose of regression is to understand the relationship between variables.

Accepted Answer

A) True 
 B)False

Question 3

Another name for a dummy variable is a binary variable.

Accepted Answer

A) True 
 B)False

Question 4

The coefficient of determination takes on values between -1 and + 1.

Accepted Answer

A) True 
 B)False

Question 5

A high correlation always implies that one variable is causing a change in the other variable.

Accepted Answer

A) True 
 B)False

Question 6

Suppose that you believe that a cubic relationship exists between the independent variable (of time)and the dependent variable Y.Which of the following would represent a valid linear regression model?

Accepted Answer

A) Y = b0 + b1 X,where X = time3 
B) Y = b0 + b1 X3,where X = time 
C) Y = b0 + 3b1 X,where X = time3 
D) Y = b0 + 3b1 X,where X = time 
E) Y = b0 + b1 X,where X = time1/3 
A) Y = b0 + b1 X,where X = time3 
B) Y = b0 + b1 X3,where X = time 
C) Y = b0 + 3b1 X,where X = time3 
D) Y = b0 + 3b1 X,where X = time 
E) Y = b0 + b1 X,where X = time1/3

Question 7

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 
E) SSE = Actual Value - Predicted Value 
A) SST = SSR + SSE 
B) SSR = SST + SSE 
C) SSE = SSR + SST 
D) SST = SSC + SSR 
E) SSE = Actual Value - Predicted Value

Question 8

An F-test is used to determine if there is a relationship between the dependent and independent variables.

Accepted Answer

A) True 
 B)False

Question 9

The standard deviation of the regression is also called ________.

Accepted Answer

the standa

Question 10

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. 
E) Using a regression equation beyond the range of X is very questionable. 
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. 
E) Using a regression equation beyond the range of X is very questionable.

Question 11

A prediction equation for starting salaries (in $1,000s)and SAT scores was performed using simple linear regression.In the regression printout shown below,what can be said about the level of significance for the overall model?

Accepted Answer

A) SAT is not a good predictor for starting salary. 
B) The significance level for the intercept indicates the model is not valid. 
C) The significance level for SAT indicates the slope is equal to zero. 
D) The significance level for SAT indicates the slope is not equal to zero. 
E) None of the above 
A) SAT is not a good predictor for starting salary. 
B) The significance level for the intercept indicates the model is not valid. 
C) The significance level for SAT indicates the slope is equal to zero. 
D) The significance level for SAT indicates the slope is not equal to zero. 
E) None of the above

Question 12

The problem of a nonlinear relationship is detected in residual analysis by which of the following?

Accepted Answer

A) a cone pattern 
B) an arched pattern 
C) a random pattern 
D) an increasing pattern 
E) a decreasing pattern 
A) a cone pattern 
B) an arched pattern 
C) a random pattern 
D) an increasing pattern 
E) a decreasing pattern

Question 13

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. 
E) None of the above 
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. 
E) None of the above

Question 14

Which of the following is an assumption of the regression model?

Accepted Answer

A) The errors are independent. 
B) The errors are not normally distributed. 
C) The errors have a standard deviation of zero. 
D) The errors have an irregular variance. 
E) The errors follow a cone pattern. 
A) The errors are independent. 
B) The errors are not normally distributed. 
C) The errors have a standard deviation of zero. 
D) The errors have an irregular variance. 
E) The errors follow a cone pattern.

Question 15

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 three categories: Government-Funded,Private-Pay,and Other.Her model is

Accepted Answer

A) Y = b0. 
B) Y = b0 + b1 X1. 
C) Y = b0 + b1 X1 + b2 X2. 
D) Y = b0 + b1 X1 + b2 X2 + b3 X3. 
E) Y = b0 + b1 X1 + b2 X2 + b3 X3 + b4 X4. 
A) Y = b0. 
B) Y = b0 + b1 X1. 
C) Y = b0 + b1 X1 + b2 X2. 
D) Y = b0 + b1 X1 + b2 X2 + b3 X3. 
E) Y = b0 + b1 X1 + b2 X2 + b3 X3 + b4 X4.

Question 16

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

Question 17

The sum of the squares total (SST)

Accepted Answer

A) measures the total variability in Y about the mean. 
B) measures the total variability in X about the mean. 
C) measures the variability in Y about the regression line. 
D) measures the variability in X about the regression line. 
E) indicates how much of the total variability in Y is explained by the regression model. 
A) measures the total variability in Y about the mean. 
B) measures the total variability in X about the mean. 
C) measures the variability in Y about the regression line. 
D) measures the variability in X about the regression line. 
E) indicates how much of the total variability in Y is explained by the regression model.

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

When an independent variable is correlated with one other independent variable,the variables are said to be

Accepted Answer

A) collinear. 
B) pairwise. 
C) independent. 
D) mutually exclusive. 
E) None of the above 
A) collinear. 
B) pairwise. 
C) independent. 
D) mutually exclusive. 
E) None of the above

Question 20

The ________ measures the variability in Y about the regression line.

Accepted Answer

SSE or sum

Exam 4: Regression Models

A variable should be added to the model regardless of the impact (increase or decrease)on the adjusted r2 value.

One purpose of regression is to understand the relationship between variables.

Another name for a dummy variable is a binary variable.

The coefficient of determination takes on values between -1 and + 1.

A high correlation always implies that one variable is causing a change in the other variable.

Suppose that you believe that a cubic relationship exists between the independent variable (of time)and the dependent variable Y.Which of the following would represent a valid linear regression model?

Which of the following equalities is correct?

An F-test is used to determine if there is a relationship between the dependent and independent variables.

The standard deviation of the regression is also called ________.

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

A prediction equation for starting salaries (in $1,000s)and SAT scores was performed using simple linear regression.In the regression printout shown below,what can be said about the level of significance for the overall model?

The problem of a nonlinear relationship is detected in residual analysis by which of the following?

The mean square error (MSE)is

Which of the following is an assumption of the regression model?

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 three categories: Government-Funded,Private-Pay,and Other.Her model is

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

The sum of the squares total (SST)

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

When an independent variable is correlated with one other independent variable,the variables are said to be

The ________ measures the variability in Y about the regression line.

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

A variable should be added to the model regardless of the impact (increase or decrease)on the adjusted r² value.