Question 1

As more variables are added to the model,what happens to the r2 value?

Accepted Answer

It usually

Question 2

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 3

The problem of nonconstant error variance 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 4

The ________ indicates how much total variability in Y is explained by the regression model.

Accepted Answer

SSR or sum

Question 5

What can be said about a correlation coefficient of +1?

Accepted Answer

This is a perfect positive cor

Question 6

The errors in a regression model are assumed to have an increasing mean.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following statements is false concerning the hypothesis testing procedure for a regression model?

Accepted Answer

A) The F-test statistic is used. 
B) The null hypothesis is that the true slope coefficient is equal to zero. 
C) The null hypothesis is rejected if the adjusted r2 is above the critical value. 
D) An α level must be selected. 
E) The alternative hypothesis is that the true slope coefficient is not equal to zero. 
A) The F-test statistic is used. 
B) The null hypothesis is that the true slope coefficient is equal to zero. 
C) The null hypothesis is rejected if the adjusted r2 is above the critical value. 
D) An α level must be selected. 
E) The alternative hypothesis is that the true slope coefficient is not equal to zero.

Question 8

Describe a residual plot.

Accepted Answer

A residual plot is a plot of t

Question 9

When the independent variables are correlated with each other,________ is said to exist.

Accepted Answer

multicolli

Question 10

Which of the following statements is/are not true about regression models?

Accepted Answer

A) Estimates of the slope are found from sample data. 
B) The regression line minimizes the sum of the squared errors. 
C) The error is found by subtracting the actual data value from the predicted data value. 
D) The dependent variable is the explanatory variable. 
E) The intercept coefficient is not typically interpreted. 
A) Estimates of the slope are found from sample data. 
B) The regression line minimizes the sum of the squared errors. 
C) The error is found by subtracting the actual data value from the predicted data value. 
D) The dependent variable is the explanatory variable. 
E) The intercept coefficient is not typically interpreted.

Question 11

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 12

The regression model assumes the errors are normally distributed.

Accepted Answer

A) True 
 B)False

Question 13

When the significance level is small enough in the F-test,we can reject the null hypothesis that there is no linear relationship.

Accepted Answer

A) True 
 B)False

Question 14

The error standard deviation is estimated by MSE.

Accepted Answer

A) True 
 B)False

Question 15

The sum of squared error (SSE)is

Accepted Answer

A) a measure of the total variation in Y about the mean. 
B) a measure of the total variation in X about the mean. 
C) a measure in the variation of Y about the regression line. 
D) a measure in the variation of X about the regression line. 
E) None of the above 
A) a measure of the total variation in Y about the mean. 
B) a measure of the total variation in X about the mean. 
C) a measure in the variation of Y about the regression line. 
D) a measure in the variation of X about the regression line. 
E) None of the above

Question 16

A scatter diagram is a graphical depiction of the relationship between the dependent and independent variables.

Accepted Answer

A) True 
 B)False

Question 17

In regression,an independent variable is sometimes called a response variable.

Accepted Answer

A) True 
 B)False

Question 18

An air conditioning and heating repair firm conducted a study to determine if the average outside temperature,thickness of the insulation,and age of the heating equipment could be used to predict the electric bill for a home during the winter months in Houston,Texas.The resulting regression equation was:
Y = 256.89 - 1.45X1 - 11.26X2 + 6.10X3,where Y = monthly cost,X1 = average temperature,X2 = insulation thickness,and X3 = age of heating equipment
(a)If December has an average temperature of 45 degrees and the heater is 2 years old with insulation that is 6 inches thick,what is the forecasted monthly electric bill?
(b)If January has an average temperature of 40 degrees and the heating equipment is 12 years old with insulation that is 2 inches thick,what is the forecasted monthly electric bill?

Accepted Answer

(a)$256.89 - 1.45(45)- 11.26(6

Question 19

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 20

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

Exam 4: Regression Models

As more variables are added to the model,what happens to the r2 value?

Which of the following statements is true about r2?

The problem of nonconstant error variance is detected in residual analysis by which of the following?

The ________ indicates how much total variability in Y is explained by the regression model.

What can be said about a correlation coefficient of +1?

The errors in a regression model are assumed to have an increasing mean.

Which of the following statements is false concerning the hypothesis testing procedure for a regression model?

Describe a residual plot.

When the independent variables are correlated with each other,________ is said to exist.

Which of the following statements is/are not true about regression models?

The regression model assumes the errors are normally distributed.

When the significance level is small enough in the F-test,we can reject the null hypothesis that there is no linear relationship.

The error standard deviation is estimated by MSE.

The sum of squared error (SSE)is

A scatter diagram is a graphical depiction of the relationship between the dependent and independent variables.

In regression,an independent variable is sometimes called a response variable.

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

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

As more variables are added to the model,what happens to the r² value?

Which of the following statements is true about r²?