Question 1

The errors in a regression model are assumed to have zero variance.

Accepted Answer

A) True 
 B)False

Question 2

A dummy variable can be assigned up to three values.

Accepted Answer

A) True 
 B)False

Question 3

Discuss the relationship between r2 and adjusted r2.

Accepted Answer

The value of r² can never decrease when m

Question 4

Multicollinearity exists when a variable is correlated to other variables.

Accepted Answer

A) True 
 B)False

Question 5

The regression line minimizes the sum of the ________.

Accepted Answer

The answer of The regression line minimizes the sum of...

Question 6

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 7

There is no relationship between variables unless the data points lie in a straight line.

Accepted Answer

A) True 
 B)False

Question 8

The standard deviation of the regression is also called ________.

Accepted Answer

the standa

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

In regression, a dependent variable is sometimes called a predictor variable.

Accepted Answer

A) True 
 B)False

Question 11

A healthcare executive is using regression to predict total revenues. She is deciding whether or not to include both patient length of stay and insurance type in her model. Her first regression model only included patient length of stay. The resulting r2 was .83, with an adjusted r2 of .82 and her level of significance was .003. In the second model, she included both patient length of stay and insurance type. The r2 was .84 and the adjusted r2 was .80 for the second model and the level of significance did not change. Which of the following statements is true?

Accepted Answer

A)  The second model is a better model. 
B)  The first model is a better model. 
C)  The r2 increased when additional variables were added because these variables significantly contribute to the prediction of total revenues. 
D)  The adjusted r2 always increases when additional variables are added to the model. 
E)  None of the above statements are true. 
A)  The second model is a better model. 
B)  The first model is a better model. 
C)  The r2 increased when additional variables were added because these variables significantly contribute to the prediction of total revenues. 
D)  The adjusted r2 always increases when additional variables are added to the model. 
E)  None of the above statements are true.

Question 12

The ________ measures the total variability in Y about the mean.

Accepted Answer

SST or sum

Question 13

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. 
E)  Neither binary nor dummy variables are necessary for the regression model. 
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. 
E)  Neither binary nor dummy variables are necessary for the regression model.

Question 14

A prediction equation for sales and payroll was performed using simple linear regression. In the regression printout shown below, which of the following statements is/are not true?

Accepted Answer

A)  Payroll is a good predictor of Sales based on α = 0.05. 
B)  There is evidence of a positive linear relationship between Sales and Payroll based on α = 0.05. 
C)  Payroll is not a good predictor of Sales based on α = 0.01. 
D)  The coefficient of determination is equal to 0.833333. 
E)  Payroll is the independent variable. 
A)  Payroll is a good predictor of Sales based on α = 0.05. 
B)  There is evidence of a positive linear relationship between Sales and Payroll based on α = 0.05. 
C)  Payroll is not a good predictor of Sales based on α = 0.01. 
D)  The coefficient of determination is equal to 0.833333. 
E)  Payroll is the independent variable.

Question 15

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 16

The SSE measures the total variability in the independent variable about the regression line.

Accepted Answer

A) True 
 B)False

Question 17

Transformations may be used when nonlinear relationships exist between variables.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following statements is true regarding a scatter diagram?

Accepted Answer

A)  It provides very little information about the relationship between the regression variables. 
B)  It is a plot of the independent and dependent variables. 
C)  It is a line chart of the independent and dependent variables. 
D)  It has a value between -1 and +1. 
E)  It gives the percent of variation in the dependent variable that is explained by the independent variable. 
A)  It provides very little information about the relationship between the regression variables. 
B)  It is a plot of the independent and dependent variables. 
C)  It is a line chart of the independent and dependent variables. 
D)  It has a value between -1 and +1. 
E)  It gives the percent of variation in the dependent variable that is explained by the independent variable.

Question 19

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. 
E)  It ranges in value from -1 to + 1. 
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. 
E)  It ranges in value from -1 to + 1.

Question 20

For statistical tests of significance about the coefficients, the null hypothesis is that the slope is 1.

Accepted Answer

A) True 
 B)False

The errors in a regression model are assumed to have zero variance.

A dummy variable can be assigned up to three values.

Discuss the relationship between r² and adjusted r².

Multicollinearity exists when a variable is correlated to other variables.

The regression line minimizes the sum of the ________.

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

There is no relationship between variables unless the data points lie in a straight line.

The standard deviation of the regression is also called ________.

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

In regression, a dependent variable is sometimes called a predictor variable.

The ________ measures the total variability in Y about the mean.

A prediction equation for sales and payroll was performed using simple linear regression. In the regression printout shown below, which of the following statements is/are not true?

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

The SSE measures the total variability in the independent variable about the regression line.

Transformations may be used when nonlinear relationships exist between variables.

Which of the following statements is true regarding a scatter diagram?

Which of the following statements is true about r²?

For statistical tests of significance about the coefficients, the null hypothesis is that the slope is 1.

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 and Assignment Models

Integer Programming, Goal Programming, and Nonlinear Programming

Network Models

Project Management

Waiting Lines and Queuing Theory Models

Simulation Modeling

Markov Analysis

Statistical Quality Control

Filters

Exam 4: Regression Models

The errors in a regression model are assumed to have zero variance.

A dummy variable can be assigned up to three values.

Discuss the relationship between r2 and adjusted r2.

Multicollinearity exists when a variable is correlated to other variables.

The regression line minimizes the sum of the ________.

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

There is no relationship between variables unless the data points lie in a straight line.

The standard deviation of the regression is also called ________.

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

In regression, a dependent variable is sometimes called a predictor variable.

The ________ measures the total variability in Y about the mean.

A prediction equation for sales and payroll was performed using simple linear regression. In the regression printout shown below, which of the following statements is/are not true?

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

The SSE measures the total variability in the independent variable about the regression line.

Transformations may be used when nonlinear relationships exist between variables.

Which of the following statements is true regarding a scatter diagram?

Which of the following statements is true about r2?

For statistical tests of significance about the coefficients, the null hypothesis is that the slope is 1.

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 and Assignment Models

Integer Programming, Goal Programming, and Nonlinear Programming

Network Models

Project Management

Waiting Lines and Queuing Theory Models

Simulation Modeling

Markov Analysis

Statistical Quality Control

Filters

Discuss the relationship between r² and adjusted r².

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

Which of the following statements is true about r²?