Question 1

The diagram below illustrates data with a

Accepted Answer

A) negative correlation coefficient. 
B) zero correlation coefficient. 
C) positive correlation coefficient. 
D) correlation coefficient equal to +1. 
A) negative correlation coefficient. 
B) zero correlation coefficient. 
C) positive correlation coefficient. 
D) correlation coefficient equal to +1. C

Question 2

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? SUMMARY OUTPUT
  ANOVA

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. 
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. D

Question 3

Which of the following is not an assumption of the regression model?

Accepted Answer

A) The errors are independent. 
B) The errors should have a standard deviation equal to one. 
C) The errors are normally distributed. 
D) The errors have constant variance. 
A) The errors are independent. 
B) The errors should have a standard deviation equal to one. 
C) The errors are normally distributed. 
D) The errors have constant variance. B

Question 4

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents an independent variable?

Accepted Answer

A) the X1 
B) the Y 
C) the β1 
D) the ε 
A) the X1 
B) the Y 
C) the β1 
D) the ε

Question 5

The correlation coefficient resulting from a particular regression analysis was 0.25.What was the coefficient of determination?

Accepted Answer

A) 0.5 
B) -0.5 
C) 0.0625 
D) There is insufficient information to answer the question. 
A) 0.5 
B) -0.5 
C) 0.0625 
D) There is insufficient information to answer the question.

Question 6

If multicollinearity exists, then individual interpretation of the variables is questionable, but the overall model is still good for prediction purposes.

Accepted Answer

A) True 
 B)False

Question 7

Table 4.1
SUMMARY OUTPUT
   ANOVA
    
-Consider the output shown in Table 4.1.How many observations were used to develop the estimates of the regression coefficients?

Accepted Answer

A) 13 
B) 16 
C) 20 
D) 23 
A) 13 
B) 16 
C) 20 
D) 23

Question 8

Which of these equations is a linear model?

Accepted Answer

A) Y = b0 + b1 ln(X)where X = time 
B) Y = b0 + b1 X, where X = ln(time) 
C) Y = b0 + b1 X, where X = time2 
D) Y = b0 + b1 X, where X = time 
A) Y = b0 + b1 ln(X)where X = time 
B) Y = b0 + b1 X, where X = ln(time) 
C) Y = b0 + b1 X, where X = time2 
D) Y = b0 + b1 X, where X = time

Question 9

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 10

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 11

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents a coefficient of an independent variable?

Accepted Answer

A) the X1 
B) the Y 
C) the β1 
D) the ε 
A) the X1 
B) the Y 
C) the β1 
D) the ε

Question 12

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. 
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.

Question 13

The relationship between hours of preparation and average score on a field exam routinely administered Friday and Saturday evenings is captured in this plot.   Which of these statements is best?

Accepted Answer

A) A linear transformation would permit a good regression line fit. 
B) A squared transformation would permit a good regression fit. 
C) A cubic transformation would permit a good regression fit. 
D) An inverse transformation would permit a good regression fit 
A) A linear transformation would permit a good regression line fit. 
B) A squared transformation would permit a good regression fit. 
C) A cubic transformation would permit a good regression fit. 
D) An inverse transformation would permit a good regression fit

Question 14

The multiple regression model includes several intercept terms.

Accepted Answer

A) True 
 B)False

Question 15

Which of these statements is best?

Accepted Answer

A) In regression, an independent variable is sometimes called a response variable. 
B) A scatter diagram is a graphical depiction of the relationship between the dependent and independent variables. 
C) In a scatter diagram, the dependent variable is typically plotted on the horizontal axis. 
D) There is no relationship between variables unless the data points lie in a straight line. 
A) In regression, an independent variable is sometimes called a response variable. 
B) A scatter diagram is a graphical depiction of the relationship between the dependent and independent variables. 
C) In a scatter diagram, the dependent variable is typically plotted on the horizontal axis. 
D) There is no relationship between variables unless the data points lie in a straight line.

Question 16

List four pitfalls of regression.

Accepted Answer

If the assumptions are not met, the stat

Question 17

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. 
A) collinear. 
B) pairwise. 
C) independent. 
D) mutually exclusive.

Question 18

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents a dependent variable?

Accepted Answer

A) the X1 
B) the Y 
C) the β1 
D) the ε 
A) the X1 
B) the Y 
C) the β1 
D) the ε

Question 19

A savvy egg quality forecaster develops a linear model using the transformation X2 = (Haugh Units)2.Which of these statements about the equation Ŷ = 15.2-7X1 -3.5X2 is best?

Accepted Answer

A) Haugh Units have twice the impact as Haugh Units squared. 
B) We should not try to interpret the coefficients of the variables due to the correlation between X1 and X2. 
C) Y = The curvature of the relationship is more important than the linear component. 
D) Y = The intercept term in the model is twice as important at the value of the Haugh Units. 
A) Haugh Units have twice the impact as Haugh Units squared. 
B) We should not try to interpret the coefficients of the variables due to the correlation between X1 and X2. 
C) Y = The curvature of the relationship is more important than the linear component. 
D) Y = The intercept term in the model is twice as important at the value of the Haugh Units.

Question 20

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. 
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.

Exam 4: Regression Models

The diagram below illustrates data with a

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? SUMMARY OUTPUT ANOVA

Which of the following is not an assumption of the regression model?

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents an independent variable?

The correlation coefficient resulting from a particular regression analysis was 0.25.What was the coefficient of determination?

If multicollinearity exists, then individual interpretation of the variables is questionable, but the overall model is still good for prediction purposes.

Table 4.1 SUMMARY OUTPUT ANOVA -Consider the output shown in Table 4.1.How many observations were used to develop the estimates of the regression coefficients?

Which of these equations is a linear model?

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

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents a coefficient of an independent variable?

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

The relationship between hours of preparation and average score on a field exam routinely administered Friday and Saturday evenings is captured in this plot. Which of these statements is best?

The multiple regression model includes several intercept terms.

Which of these statements is best?

List four pitfalls of regression.

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

In the model Y = β0 + β1X1 + β2X2 + ε, which of these parameters represents a dependent variable?

A savvy egg quality forecaster develops a linear model using the transformation X2 = (Haugh Units)2.Which of these statements about the equation Ŷ = 15.2-7X1 -3.5X2 is best?

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

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

In the model Y = β₀ + β₁X₁ + β₂X₂ + ε, which of these parameters represents an independent variable?

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

In the model Y = β₀ + β₁X₁ + β₂X₂ + ε, which of these parameters represents a coefficient of an independent variable?

In the model Y = β₀ + β₁X₁ + β₂X₂ + ε, which of these parameters represents a dependent variable?

A savvy egg quality forecaster develops a linear model using the transformation X₂ = (Haugh Units)².Which of these statements about the equation Ŷ = 15.2-7X₁ -3.5X₂ is best?