Consider the regression model = 30 + 15x1 - 10x2 + 5x1x2.A 1-unit increase in x2,while holding x1 constant at 1,changes the value of y,on average,by:

A) -5 B) -10 C) +10 D) +5 A) -5 B) -10 C) +10 D) +5

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: You are interested in examining the factors that determine the average length of stay in a hospital across states.You collect data on the following variables: Y = statewide average hospital stay XS1U1B11S1U1B0 = median state income XS1U1B12S1U1B0 = 1 if the state is in the Northeast,0 otherwise XS1U1B13S1U1B0 = 1 if the state is in the South,0 otherwise XS1U1B14S1U1B0 = 1 if the state is in the Midwest,0 otherwise XS1U1B15S1U1B0 = 1 if the state is in the West,0 otherwise -You run the following regression Y = β0 + β1X1 + β2X2 + β3X3 + β5X5.How much longer would we expect to stay in a hospital in the Northeast than in a hospital in the Midwest?

A) β0 B) β0 + β5 C) β2 D) β0 - β4 A) β0 B) β0 + β5 C) β2 D) β0 - β4

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: An economist is in the process of developing a model to predict the price of gold.She believes that the two most important variables are the price of a barrel of oil (xS1U1B11S1U1B0)and the interest rate (xS1U1B12S1U1B0).She proposes the model y = βS1U1B10S1U1B0 + βS1U1B11S1U1B0xS1U1B11S1U1B0 + βS1U1B12S1U1B0xS1U1B12S1U1B0 + βS1U1B13S1U1B0xS1U1B11S1U1B0xS1U1B13S1U1B0 + ε.A random sample of 20 daily observations was taken.The computer output is shown below. THE REGRESSION EQUATION IS y = 115.6 + 22.3xS1U1B11S1U1B0 + 14.7xS1U1B12S1U1B0 - 1.36xS1U1B11S1U1B0xS1U1B12S1U1B0 S = 20.9 R-Sq = 55.4% ANALYSIS OF VARIANCE -An economist estimates the regression model yi= β0 + β1x1i + β2x2i + εi.The estimates of the parameters β1 and β2 are not very large compared with their respective standard errors.But the size of the coefficient of determination indicates quite a strong relationship between the dependent variable and the pair of independent variables.Having obtained these results,the economist strongly suspects the presence of multicollinearity.Since his chief interest is in the influence of X1 on the dependent variable,he decides that he will avoid the problem of multicollinearity by regressing Y on X1 alone.Comment on this strategy.

If Y is,in fact,strongly influenced by X

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: You are interested in examining the factors that determine the average length of stay in a hospital across states.You collect data on the following variables: Y = statewide average hospital stay XS1U1B11S1U1B0 = median state income XS1U1B12S1U1B0 = 1 if the state is in the Northeast,0 otherwise XS1U1B13S1U1B0 = 1 if the state is in the South,0 otherwise XS1U1B14S1U1B0 = 1 if the state is in the Midwest,0 otherwise XS1U1B15S1U1B0 = 1 if the state is in the West,0 otherwise -You run the following regression: Y = β0 + β1X1 + β2X2 + β3X3 + β5X5.What effect does being a state in the Northeast have on the average length of hospital stay?

A) β0 B) β0 + β5 C) β2 D) β0 + β2 A) β0 B) β0 + β5 C) β2 D) β0 + β2

Exam 13: Additional Topics in Regression Analysis

Consider the regression model = 30 + 15x₁ - 10x₂ + 5x₁x₂.A 1-unit increase in x₂,while holding x₁ constant at 1,changes the value of y,on average,by:

(Multiple Choice)

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Question 21

You are interested in examining the factors that determine the average length of stay by patients in hospitals across states.You collect data on the following variables: Y = statewide average hospital stay X₁ = median state income X₂ = 1 if the state is in the Northeast,0 otherwise X₃ = 1 if the state is in the South,0 otherwise X₄ = 1 the state is in the Midwest,0 otherwise X₅ = 1 the state is in the West,0 otherwise Based on the data above,you run the following regression: Y = β₀ + β₁X₁ + β₂X₂ + β₃X₃ + β₄X₄. Identify the length of stay for each of the four regions using the population slopes.

(Essay)

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Question 22

A treatment variable represents a variable whose effect can be estimated with minimum variance.

(True/False)

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Question 23

The Durbin-Watson statistic d is defined as d = ,where e_t is the residual at time period t.

(True/False)

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Question 24

Considering r to be the sample estimate,which of the following is the formula for calculating the Durbin-Watson test statistic,d?

(Multiple Choice)

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Question 25

Describe a formal test for heteroscedasticity.Explain why a test with this design is likely to identify heteroscedasticity.

(Essay)

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Question 26

During the coefficient estimation stage of the model-building exercise,only the point estimates should be obtained for the multiple regression model.

(True/False)

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Question 27

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: You are interested in examining the factors that determine the average length of stay in a hospital across states.You collect data on the following variables: Y = statewide average hospital stay X₁ = median state income X₂ = 1 if the state is in the Northeast,0 otherwise X₃ = 1 if the state is in the South,0 otherwise X₄ = 1 if the state is in the Midwest,0 otherwise X₅ = 1 if the state is in the West,0 otherwise -You run the following regression Y = β₀ + β₁X₁ + β₂X₂ + β₃X₃ + β₅X₅.How much longer would we expect to stay in a hospital in the Northeast than in a hospital in the Midwest?

(Multiple Choice)

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Question 28

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following model: Y = β₀ + β₁X₁_t + β₂X₂_t + γ₃Y_t_-1.Using a sample of 36 months,we estimate this model and obtain the following results: y_t = 1.33 + 17.6x₁_t + 0.94x₂_t+ 0.39Y_t_-1 -If X₁ were to increase by 1-unit in time t,by how much would we expect Y to change in period (t + 1)?

(Multiple Choice)

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Question 29

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Suppose that a regression was run with two independent variables and 25 observations.The Durbin-Watson statistic was 2.28. -Test the hypothesis that there was no autocorrelation versus the alternative of negative autocorrelation in errors.

(Essay)

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Question 30

Experimental design methods are used extensively in the study of human behavior.

(True/False)

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Question 31

Which of the following is true of the error term used in linear regression?

(Multiple Choice)

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Question 32

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: An economist is in the process of developing a model to predict the price of gold.She believes that the two most important variables are the price of a barrel of oil (x₁)and the interest rate (x₂).She proposes the model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₃ + ε.A random sample of 20 daily observations was taken.The computer output is shown below. THE REGRESSION EQUATION IS y = 115.6 + 22.3x₁ + 14.7x₂ - 1.36x₁x₂ S = 20.9 R-Sq = 55.4% ANALYSIS OF VARIANCE -An economist estimates the regression model y_i= β₀ + β₁x₁_i+ β₂x₂_i + ε_i.The estimates of the parameters β₁ and β₂ are not very large compared with their respective standard errors.But the size of the coefficient of determination indicates quite a strong relationship between the dependent variable and the pair of independent variables.Having obtained these results,the economist strongly suspects the presence of multicollinearity.Since his chief interest is in the influence of X₁ on the dependent variable,he decides that he will avoid the problem of multicollinearity by regressing Y on X₁ alone.Comment on this strategy.

(Essay)

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Question 33

When significant predictor variables are omitted from a multiple regression model,the least squares estimates of coefficients included in the model are usually biased.

(True/False)

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Question 34

The value of the dependent variable in an earlier time period is called a lagged dependent variable.

(True/False)

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Question 35

From a statistical perspective,the regression model objectives can be divided into either a prediction of the mean of the dependent variable,or an estimation of one or more of the individual coefficients.

(True/False)

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Question 36

Dummy variables can be used to analyze data from experimental situations,which are defined by multiple-level categorical variables.

(True/False)

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Question 37

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: You are interested in examining the factors that determine the average length of stay in a hospital across states.You collect data on the following variables: Y = statewide average hospital stay X₁ = median state income X₂ = 1 if the state is in the Northeast,0 otherwise X₃ = 1 if the state is in the South,0 otherwise X₄ = 1 if the state is in the Midwest,0 otherwise X₅ = 1 if the state is in the West,0 otherwise -You run the following regression: Y = β₀ + β₁X₁ + β₂X₂ + β₃X₃ + β₅X₅.What effect does being a state in the Northeast have on the average length of hospital stay?

(Multiple Choice)

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Question 38

After running the regression Y = β₀ + β₁X₁ + β₂X₂ + β₃X₃ + β₄X₄,and examining a plot of the residuals,you have reason to suspect that there is heteroscedasticity in your model.Assume that the heteroscedasticity is directly proportional to the square of the expected value of the dependent variable.How might you estimate your model correcting for this heteroscedasticity?

(Essay)

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Question 39

Models in which the error terms do not all have the same variance are said to exhibit:

(Multiple Choice)

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Question 40

Showing 21 - 40 of 168

Consider the regression model = 30 + 15x₁ - 10x₂ + 5x₁x₂.A 1-unit increase in x₂,while holding x₁ constant at 1,changes the value of y,on average,by:

A treatment variable represents a variable whose effect can be estimated with minimum variance.

The Durbin-Watson statistic d is defined as d = ,where e_t is the residual at time period t.

Considering r to be the sample estimate,which of the following is the formula for calculating the Durbin-Watson test statistic,d?

Describe a formal test for heteroscedasticity.Explain why a test with this design is likely to identify heteroscedasticity.

During the coefficient estimation stage of the model-building exercise,only the point estimates should be obtained for the multiple regression model.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Suppose that a regression was run with two independent variables and 25 observations.The Durbin-Watson statistic was 2.28. -Test the hypothesis that there was no autocorrelation versus the alternative of negative autocorrelation in errors.

Experimental design methods are used extensively in the study of human behavior.

Which of the following is true of the error term used in linear regression?

When significant predictor variables are omitted from a multiple regression model,the least squares estimates of coefficients included in the model are usually biased.

The value of the dependent variable in an earlier time period is called a lagged dependent variable.

From a statistical perspective,the regression model objectives can be divided into either a prediction of the mean of the dependent variable,or an estimation of one or more of the individual coefficients.

Dummy variables can be used to analyze data from experimental situations,which are defined by multiple-level categorical variables.

Models in which the error terms do not all have the same variance are said to exhibit:

Describing Data: Graphical

Describing Data: Numerical

Probability

Discrete Random Variables and Probability Distributions

Continuous Random Variables and Probability Distributions

Sampling and Sampling Distributions

Estimation: Single Population

Estimation: Additional Topics

Hypothesis Testing: Single Population

Hypothesis Testing: Additional Topics

Simple Regression

Multiple Regression

Analysis of Categorical Data

Analysis of Variance

Time-Series Analysis and Forecasting

Additional Topics in Sampling

Filters

Exam 13: Additional Topics in Regression Analysis

Consider the regression model = 30 + 15x1 - 10x2 + 5x1x2.A 1-unit increase in x2,while holding x1 constant at 1,changes the value of y,on average,by:

A treatment variable represents a variable whose effect can be estimated with minimum variance.

The Durbin-Watson statistic d is defined as d = ,where et is the residual at time period t.

Considering r to be the sample estimate,which of the following is the formula for calculating the Durbin-Watson test statistic,d?

Describe a formal test for heteroscedasticity.Explain why a test with this design is likely to identify heteroscedasticity.

During the coefficient estimation stage of the model-building exercise,only the point estimates should be obtained for the multiple regression model.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Suppose that a regression was run with two independent variables and 25 observations.The Durbin-Watson statistic was 2.28. -Test the hypothesis that there was no autocorrelation versus the alternative of negative autocorrelation in errors.

Experimental design methods are used extensively in the study of human behavior.

Which of the following is true of the error term used in linear regression?

When significant predictor variables are omitted from a multiple regression model,the least squares estimates of coefficients included in the model are usually biased.

The value of the dependent variable in an earlier time period is called a lagged dependent variable.

From a statistical perspective,the regression model objectives can be divided into either a prediction of the mean of the dependent variable,or an estimation of one or more of the individual coefficients.

Dummy variables can be used to analyze data from experimental situations,which are defined by multiple-level categorical variables.

Models in which the error terms do not all have the same variance are said to exhibit:

Describing Data: Graphical

Describing Data: Numerical

Probability

Discrete Random Variables and Probability Distributions

Continuous Random Variables and Probability Distributions

Sampling and Sampling Distributions

Estimation: Single Population

Estimation: Additional Topics

Hypothesis Testing: Single Population

Hypothesis Testing: Additional Topics

Simple Regression

Multiple Regression

Analysis of Categorical Data

Analysis of Variance

Time-Series Analysis and Forecasting

Additional Topics in Sampling

Filters

Consider the regression model = 30 + 15x₁ - 10x₂ + 5x₁x₂.A 1-unit increase in x₂,while holding x₁ constant at 1,changes the value of y,on average,by:

The Durbin-Watson statistic d is defined as d = ,where e_t is the residual at time period t.