Question 1

Another name for a dummy variable is a binary variable.

Accepted Answer

A) True 
 B)False

Question 2

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

Accepted Answer

A) True 
 B)False

Question 3

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.

Question 4

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

Question 5

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

Question 6

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

Accepted Answer

A) True 
 B)False

Question 7

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

Accepted Answer

A) True 
 B)False

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

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

Question 10

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.

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

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

Accepted Answer

SSE or sum...

Question 13

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

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.

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 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

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 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.

Question 18

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.

Question 19

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

Question 20

The standard deviation of the regression is also called ________.

Accepted Answer

the standa...

Exam 4: Regression Models

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following equalities is correct?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedSSE or sum...View AnswerShow Answer

The sum of the squares total (SST)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Another name for a dummy variable is a binary variable.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The standard deviation of the regression is also called ________.

Correct Answerverifiedthe standa...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

The mean square error (MSE) is

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
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SSE or sum...
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the standa...
View Answer

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

Correct Answer
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