Question 1

Regression analysis allows the statistics practitioner to use mathematical models to realistically describe relationships between the dependent variable and independent variables.

Accepted Answer

A) True 
 B)False

Question 2

For the following regression equation  ,which combination of x1 and x2,respectively,results in the largest average value of y?

Accepted Answer

A) 3 and 5 
B) 5 and 3 
C) 6 and 3 
D) 3 and 6

Question 3

In stepwise regression,the independent variable with the largest F-statistic,or equally the smallest p-value,is chosen as the first entering variable.

Accepted Answer

A) True 
 B)False

Question 4

In the first-order model  ,a unit increase in x2,while holding x1 constant at 1,changes the value of y on average by −5 units.

Accepted Answer

A) True 
 B)False

Question 5

In multiple regression,which procedure permits variables to enter and leave the model at different stages of its development?

Accepted Answer

The answer of In multiple regression,which procedure permits variables to...

Question 6

Motorcycle Fatalities
 A traffic consultant has analyzed the factors that affect the number of motorcycle fatalities.She has come to the conclusion that two important variables are the number of motorcycle and the number of cars.She proposed the model  (the second-order model with interaction),where y = number of annual fatalities per county,xS1U1B11S1U1B0 = number of motorcycles registered in the county (in 10,000),and xS1U1B12S1U1B0 = number of cars registered in the county (in 1000).The computer output (based on a random sample of 35 counties)is shown below: THE REGRESSION EQUATION IS   S = 15.2 R−Sq = 47.2% ANALYSIS OF VARIANCE  ​ ​
-{Motorcycle Fatalities Narrative} What does the coefficient of  tell you about the model?

Accepted Answer

The answer of Motorcycle Fatalities
 A traffic consultant has analyzed...

Question 7

The model y = β0 + β1x1 + β2x2 + ε is referred to as a:

Accepted Answer

A) first-order model with one predictor variable. 
B) first-order model with two predictor variables. 
C) second-order model with one predictor variable. 
D) second-order model with two predictor variables.

Question 8

Senior Medical Students
 A professor of Anatomy wanted to develop a multiple regression model to predict the students' grades in her fourth-year medical course.She decides that the two most important factors are the student's grade point average in the first three years and the student's major.She proposes the model y = βS1U1B10S1U1B0 + βS1U1B11S1U1B0xS1U1B11S1U1B0 + βS1U1B12S1U1B0xS1U1B12S1U1B0 + βS1U1B13S1U1B0xS1U1B13S1U1B0 + ε,where y = Fourth-year medical course final score (out of 100),xS1U1B11S1U1B0 = G.P.A.in first three years (range from 0 to 12),xS1U1B12S1U1B0 = 1 if student's major is medicine and 0 if not,and xS1U1B13S1U1B0 = 1 if student's major is biology and 0 if not.The computer output is shown below. THE REGRESSION EQUATION IS y = 9.14 + 6.73xS1U1B11S1U1B0 + 10.42xS1U1B12S1U1B0 + 5.16xS1U1B13S1U1B0  S = 15.0 R−Sq = 44.2% ANALYSIS OF VARIANCE  ​ ​
-{Senior Medical Students Narrative} Predict the final grade (out of 100)in the fourth-year medical course for a biology major student who has a 10.95 G.P.A.in their first three years (range from 0 to 12).

Accepted Answer

The answer of  Senior Medical Students
 A professor of...

Question 9

When we plot x versus y,the graph of the model y = β0 + β1x + β2x2 + ε is shaped like a:

Accepted Answer

A) straight line going upwards. 
B) circle. 
C) parabola. 
D) None of these choices.

Question 10

In stepwise regression procedure,the independent variable with the largest F-statistic,or equally with the smallest p-value,is chosen as the first entering variable.The standard,also called the F-to-enter,is usually set at F equals:

Accepted Answer

A) 0 
B) 1 
C) 2 
D) 4

Question 11

Motorcycle Fatalities
 A traffic consultant has analyzed the factors that affect the number of motorcycle fatalities.She has come to the conclusion that two important variables are the number of motorcycle and the number of cars.She proposed the model  (the second-order model with interaction),where y = number of annual fatalities per county,xS1U1B11S1U1B0 = number of motorcycles registered in the county (in 10,000),and xS1U1B12S1U1B0 = number of cars registered in the county (in 1000).The computer output (based on a random sample of 35 counties)is shown below: THE REGRESSION EQUATION IS   S = 15.2 R−Sq = 47.2% ANALYSIS OF VARIANCE  ​ ​
-{Motorcycle Fatalities Narrative} Test at the 1% significance level to determine if the  term should be retained in the model.

Accepted Answer

The answer of Motorcycle Fatalities
 A traffic consultant has analyzed...

Question 12

The model y = β0 + β1x1 + β2x2 + β3x1x2 + ε is referred to as a second-order model with two predictor variables with interaction.

Accepted Answer

A) True 
 B)False

Question 13

Silver Prices An economist is in the process of developing a model to predict the price of silver.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 first-order model with interaction: 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 -{Silver Prices Narrative} Interpret the coefficient b₁.

Accepted Answer

The answer of Silver Prices
 An economist is in the...

Question 14

In explaining the amount of money spent on children's shoes each month,which of the following independent variables is best represented with an indicator variable?

Accepted Answer

A) Gender 
B) Height 
C) Age 
D) Weight

Question 15

Dummy variables are variables that can take on only two values (namely,0 or 1)and that are used to indicate the absence or presence of a particular nominal characteristic.

Accepted Answer

A) True 
 B)False

Question 16

The model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₂ + ε is a(n)____________________-order polynomial model with ____________________ predictor variables and ____________________.

Accepted Answer

The answer of The model y = β₀ + β₁x₁...

Question 17

For the following regression equation  ,a unit increase in x1 increases the value of y on average by:

Accepted Answer

A) 5 
B) 30 
C) 26 
D) an amount that depends on the value of x2

Question 18

In explaining students' test scores,which of the following independent variables would not best be represented with indicator variables?

Accepted Answer

A) Gender 
B) Race 
C) Number of hours studying for the test 
D) Marital status

Question 19

The two largest values in a correlation matrix are the .89 correlation between y and x₃,and the .83 correlation between y and x₇.During a stepwise regression analysis x₃ is the first independent variable brought into the equation.Will x₇ necessarily be next? If not,why not?

Accepted Answer

The answer of The two largest values in a correlation...

Question 20

Computer Training 
Consider the following data for two variables,x and y.The independent variable x represents the amount of training time (in hours)for a salesperson starting in a new computer store to adjust fully,and the dependent variable y represents the weekly sales (in $1000s).  Use statistical software to answer the following question(s). ​ ​
-{Computer Training Narrative} Develop an estimated regression equation of the form  .

Accepted Answer

The answer of  Computer Training 
Consider the following data...

Exam 18: Model Building

Regression analysis allows the statistics practitioner to use mathematical models to realistically describe relationships between the dependent variable and independent variables.

For the following regression equation ,which combination of x₁ and x₂,respectively,results in the largest average value of y?

In stepwise regression,the independent variable with the largest F-statistic,or equally the smallest p-value,is chosen as the first entering variable.

In the first-order model ,a unit increase in x₂,while holding x₁ constant at 1,changes the value of y on average by −5 units.

In multiple regression,which procedure permits variables to enter and leave the model at different stages of its development?

The model y = β₀ + β₁x₁ + β₂x₂ + ε is referred to as a:

When we plot x versus y,the graph of the model y = β₀ + β₁x + β₂x² + ε is shaped like a:

In stepwise regression procedure,the independent variable with the largest F-statistic,or equally with the smallest p-value,is chosen as the first entering variable.The standard,also called the F-to-enter,is usually set at F equals:

The model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₂ + ε is referred to as a second-order model with two predictor variables with interaction.

In explaining the amount of money spent on children's shoes each month,which of the following independent variables is best represented with an indicator variable?

Dummy variables are variables that can take on only two values (namely,0 or 1)and that are used to indicate the absence or presence of a particular nominal characteristic.

The model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₂ + ε is a(n)-order polynomial model with predictor variables and .

For the following regression equation ,a unit increase in x₁ increases the value of y on average by:

In explaining students' test scores,which of the following independent variables would not best be represented with indicator variables?

The two largest values in a correlation matrix are the .89 correlation between y and x₃,and the .83 correlation between y and x₇.During a stepwise regression analysis x₃ is the first independent variable brought into the equation.Will x₇ necessarily be next? If not,why not?

Exam 18: Model Building

Regression analysis allows the statistics practitioner to use mathematical models to realistically describe relationships between the dependent variable and independent variables.

For the following regression equation ,which combination of x1 and x2,respectively,results in the largest average value of y?

In stepwise regression,the independent variable with the largest F-statistic,or equally the smallest p-value,is chosen as the first entering variable.

In the first-order model ,a unit increase in x2,while holding x1 constant at 1,changes the value of y on average by −5 units.

In multiple regression,which procedure permits variables to enter and leave the model at different stages of its development?

The model y = β0 + β1x1 + β2x2 + ε is referred to as a:

When we plot x versus y,the graph of the model y = β0 + β1x + β2x2 + ε is shaped like a:

In stepwise regression procedure,the independent variable with the largest F-statistic,or equally with the smallest p-value,is chosen as the first entering variable.The standard,also called the F-to-enter,is usually set at F equals:

The model y = β0 + β1x1 + β2x2 + β3x1x2 + ε is referred to as a second-order model with two predictor variables with interaction.

In explaining the amount of money spent on children's shoes each month,which of the following independent variables is best represented with an indicator variable?

Dummy variables are variables that can take on only two values (namely,0 or 1)and that are used to indicate the absence or presence of a particular nominal characteristic.

The model y = β0 + β1x1 + β2x2 + β3x1x2 + ε is a(n)____________________-order polynomial model with ____________________ predictor variables and ____________________.

For the following regression equation ,a unit increase in x1 increases the value of y on average by:

In explaining students' test scores,which of the following independent variables would not best be represented with indicator variables?

The two largest values in a correlation matrix are the .89 correlation between y and x3,and the .83 correlation between y and x7.During a stepwise regression analysis x3 is the first independent variable brought into the equation.Will x7 necessarily be next? If not,why not?

For the following regression equation ,which combination of x₁ and x₂,respectively,results in the largest average value of y?

In the first-order model ,a unit increase in x₂,while holding x₁ constant at 1,changes the value of y on average by −5 units.

The model y = β₀ + β₁x₁ + β₂x₂ + ε is referred to as a:

When we plot x versus y,the graph of the model y = β₀ + β₁x + β₂x² + ε is shaped like a:

The model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₂ + ε is referred to as a second-order model with two predictor variables with interaction.

The model y = β₀ + β₁x₁ + β₂x₂ + β₃x₁x₂ + ε is a(n)-order polynomial model with predictor variables and .

For the following regression equation ,a unit increase in x₁ increases the value of y on average by:

The two largest values in a correlation matrix are the .89 correlation between y and x₃,and the .83 correlation between y and x₇.During a stepwise regression analysis x₃ is the first independent variable brought into the equation.Will x₇ necessarily be next? If not,why not?