Question 1

If a set of data contains no values of x that are equal to zero, then the regression coefficient, b0, has no particular meaning.

Accepted Answer

A) True 
 B)False

Question 2

In a simple regression model, the slope coefficient represents the average change in the independent variable for a one-unit change in the dependent variable.

Accepted Answer

A) True 
 B)False

Question 3

A manufacturing company is interested in predicting the number of defects that will be produced each hour on the assembly line. The managers believe that there is a relationship between the defect rate and the production rate per hour. The managers believe that they can use production rate to predict the number of defects. The following data were collected for 10 randomly selected hours.   Given these sample data, the simple linear regression model for predicting the number of defects is approximately = 5.67 + 0.048x.

Accepted Answer

A) True 
 B)False

Question 4

The fact that teachers' salaries in Wisconsin are correlated with egg prices in Texas means that the two variables are spuriously correlated since a change in one variable could not cause the change in the other.

Accepted Answer

A) True 
 B)False

Question 5

When regression analysis is used for descriptive purposes, two of the main items of interest are whether the sign on the regression slope coefficient is positive or negative and whether the regression slope coefficient is significantly different from zero.

Accepted Answer

A) True 
 B)False

Question 6

Consider the following partially completed computer printout for a regression analysis where the dependent variable is the price of a personal computer and the independent variable is the size of the hard drive.   Based on the information provided, what is the F statistic?

Accepted Answer

A)  About 8 .33 
B)  Just over 2.35 
C)  About 4.76 
D)  About 69.5 
A)  About 8 .33 
B)  Just over 2.35 
C)  About 4.76 
D)  About 69.5

Question 7

The prediction interval developed from a simple linear regression model will be at its narrowest point when the value of x used to predict y is equal to the mean value of x.

Accepted Answer

A) True 
 B)False

Question 8

Explain what the correlation coefficient measures and some detail of the key issues associated with it. Be sure to also discuss the concept of spurious correlation.

Accepted Answer

Correlation is the term used to indicate

Question 9

The standard error of the estimate for a simple linear regression model measures the variation in the slope coefficient from sample to sample.

Accepted Answer

A) True 
 B)False

Question 10

In conducting a hypothesis test on the correlation between a pair of variables, we assume that each variable is normally and independently distributed.

Accepted Answer

A) True 
 B)False

Question 11

State University recently randomly sampled ten students and analyzed grade point average (GPA) and number of hours worked off-campus per week. The following data were observed:   In this study the independent variable is the number of hours worked off campus per week.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following is a correct interpretation for the regression slope coefficient?

Accepted Answer

A)  For a one-unit change in y, we can expect the value of the independent variable to change by b1 units on average. 
B)  For each unit change in x, the dependent variable will change by b1 units. 
C)  The average change in y of a one-unit change in x will be b1 units. 
D)  The average change in x of a one-unit change in y will be b1 units. 
A)  For a one-unit change in y, we can expect the value of the independent variable to change by b1 units on average. 
B)  For each unit change in x, the dependent variable will change by b1 units. 
C)  The average change in y of a one-unit change in x will be b1 units. 
D)  The average change in x of a one-unit change in y will be b1 units.

Question 13

If the correlation between the dependent variable and the independent variable is negative, the standard error of the regression slope coefficient in a simple linear regression model will also be negative.

Accepted Answer

A) True 
 B)False

Question 14

Given a sample correlation r = -0.5 and a sample size of n = 30, the test statistic for testing whether the two variables are significantly correlated is approximately t = -3.055.

Accepted Answer

A) True 
 B)False

Question 15

A recent study of 15 shoppers showed that the correlation between the time spent in the store and the dollars spent was 0.235. Using a significance level equal to 0.05, which of the following is true?

Accepted Answer

A)  The null hypothesis that the population mean is equal to zero should be rejected and we should conclude that the true correlation is not equal to zero. 
B)  Based on the sample data there is not enough evidence to conclude that the true correlation is different from zero. 
C)  The sample correlation coefficient could be zero since the test statistic does not fall in the rejection region. 
D)  The null hypothesis should be rejected because the test statistic exceeds the critical value. 
A)  The null hypothesis that the population mean is equal to zero should be rejected and we should conclude that the true correlation is not equal to zero. 
B)  Based on the sample data there is not enough evidence to conclude that the true correlation is different from zero. 
C)  The sample correlation coefficient could be zero since the test statistic does not fall in the rejection region. 
D)  The null hypothesis should be rejected because the test statistic exceeds the critical value.

Question 16

When constructing a scatter plot, the dependent variable is placed on the vertical axis and the independent variable is placed on the horizontal axis.

Accepted Answer

A) True 
 B)False

Question 17

A study was recently performed by the Internal Revenue Service to determine how much tip income waiters and waitresses should make based on the size of the bill at each table. A random sample of bills and resulting tips were collected. These data are shown as follows:   Based upon these data, what is the approximate predicted value for tips if the total bill is $100?

Accepted Answer

A)  $15.55 
B)  $20.61 
C)  $26.03 
D)  $12.88 
A)  $15.55 
B)  $20.61 
C)  $26.03 
D)  $12.88

Question 18

A research study has stated that the income earned by working individuals is correlated at a .64 value with the years of experience of the individual. Given this, the points of the scatter plot would fall on an inclined straight line that has a slope equal to .64.

Accepted Answer

A) True 
 B)False

Question 19

The following regression output is available. Notice that some of the values are missing.   Given this information, what is the standard error of the estimate for the regression model?

Accepted Answer

A)  About 36.18 
B)  Approximately 6.02 
C)  About 1.98 
D)  3.91 
A)  About 36.18 
B)  Approximately 6.02 
C)  About 1.98 
D)  3.91

Question 20

If two variables are uncorrelated, the sample correlation coefficient will be r = 0.00.

Accepted Answer

A) True 
 B)False

If a set of data contains no values of x that are equal to zero, then the regression coefficient, b0, has no particular meaning.

In a simple regression model, the slope coefficient represents the average change in the independent variable for a one-unit change in the dependent variable.

The fact that teachers' salaries in Wisconsin are correlated with egg prices in Texas means that the two variables are spuriously correlated since a change in one variable could not cause the change in the other.

When regression analysis is used for descriptive purposes, two of the main items of interest are whether the sign on the regression slope coefficient is positive or negative and whether the regression slope coefficient is significantly different from zero.

Consider the following partially completed computer printout for a regression analysis where the dependent variable is the price of a personal computer and the independent variable is the size of the hard drive. Based on the information provided, what is the F statistic?

The prediction interval developed from a simple linear regression model will be at its narrowest point when the value of x used to predict y is equal to the mean value of x.

Explain what the correlation coefficient measures and some detail of the key issues associated with it. Be sure to also discuss the concept of spurious correlation.

The standard error of the estimate for a simple linear regression model measures the variation in the slope coefficient from sample to sample.

In conducting a hypothesis test on the correlation between a pair of variables, we assume that each variable is normally and independently distributed.

State University recently randomly sampled ten students and analyzed grade point average (GPA) and number of hours worked off-campus per week. The following data were observed: In this study the independent variable is the number of hours worked off campus per week.

Which of the following is a correct interpretation for the regression slope coefficient?

If the correlation between the dependent variable and the independent variable is negative, the standard error of the regression slope coefficient in a simple linear regression model will also be negative.

Given a sample correlation r = -0.5 and a sample size of n = 30, the test statistic for testing whether the two variables are significantly correlated is approximately t = -3.055.

A recent study of 15 shoppers showed that the correlation between the time spent in the store and the dollars spent was 0.235. Using a significance level equal to 0.05, which of the following is true?

When constructing a scatter plot, the dependent variable is placed on the vertical axis and the independent variable is placed on the horizontal axis.

A research study has stated that the income earned by working individuals is correlated at a .64 value with the years of experience of the individual. Given this, the points of the scatter plot would fall on an inclined straight line that has a slope equal to .64.

The following regression output is available. Notice that some of the values are missing. Given this information, what is the standard error of the estimate for the regression model?

If two variables are uncorrelated, the sample correlation coefficient will be r = 0.00.

The Where, Why, and How of Data Collection

Graphs, Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introducing Business Analytics

Introduction to Decision Analysis

Introduction to Quality and Statistical Process Control

Filters

Exam 14: Introduction to Linear Regression and Correlation Analysis

If a set of data contains no values of x that are equal to zero, then the regression coefficient, b0, has no particular meaning.

In a simple regression model, the slope coefficient represents the average change in the independent variable for a one-unit change in the dependent variable.

The fact that teachers' salaries in Wisconsin are correlated with egg prices in Texas means that the two variables are spuriously correlated since a change in one variable could not cause the change in the other.

When regression analysis is used for descriptive purposes, two of the main items of interest are whether the sign on the regression slope coefficient is positive or negative and whether the regression slope coefficient is significantly different from zero.

Consider the following partially completed computer printout for a regression analysis where the dependent variable is the price of a personal computer and the independent variable is the size of the hard drive. Based on the information provided, what is the F statistic?

The prediction interval developed from a simple linear regression model will be at its narrowest point when the value of x used to predict y is equal to the mean value of x.

Explain what the correlation coefficient measures and some detail of the key issues associated with it. Be sure to also discuss the concept of spurious correlation.

The standard error of the estimate for a simple linear regression model measures the variation in the slope coefficient from sample to sample.

In conducting a hypothesis test on the correlation between a pair of variables, we assume that each variable is normally and independently distributed.

State University recently randomly sampled ten students and analyzed grade point average (GPA) and number of hours worked off-campus per week. The following data were observed: In this study the independent variable is the number of hours worked off campus per week.

Which of the following is a correct interpretation for the regression slope coefficient?

If the correlation between the dependent variable and the independent variable is negative, the standard error of the regression slope coefficient in a simple linear regression model will also be negative.

Given a sample correlation r = -0.5 and a sample size of n = 30, the test statistic for testing whether the two variables are significantly correlated is approximately t = -3.055.

A recent study of 15 shoppers showed that the correlation between the time spent in the store and the dollars spent was 0.235. Using a significance level equal to 0.05, which of the following is true?

When constructing a scatter plot, the dependent variable is placed on the vertical axis and the independent variable is placed on the horizontal axis.

A research study has stated that the income earned by working individuals is correlated at a .64 value with the years of experience of the individual. Given this, the points of the scatter plot would fall on an inclined straight line that has a slope equal to .64.

The following regression output is available. Notice that some of the values are missing. Given this information, what is the standard error of the estimate for the regression model?

If two variables are uncorrelated, the sample correlation coefficient will be r = 0.00.

The Where, Why, and How of Data Collection

Graphs, Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introducing Business Analytics

Introduction to Decision Analysis

Introduction to Quality and Statistical Process Control

Filters