Question 1

The coefficient of determination   tells you

Accepted Answer

A) that the coefficient of correlation (r)is larger than 1. 
B) whether r has any significance. 
C) that you should not partition the total variation. 
D) the proportion of total variation that is explained. 
A) that the coefficient of correlation (r)is larger than 1. 
B) whether r has any significance. 
C) that you should not partition the total variation. 
D) the proportion of total variation that is explained.

Question 2

SCENARIO 13-11 A computer software developer would like to use the number of downloads (in thousands)for the trial version of his new shareware to predict the amount of revenue (in thousands of dollars) he can make on the full version of the new shareware.Following is the output from a simple linear regression along with the residual plot and normal probability plot obtained from a data set of 30 different sharewares that he has developed:      
-Referring to Scenario 13-11, which of the following is the correct interpretation for the slope coefficient?

Accepted Answer

A) For each decrease of 1 thousand downloads, the expected revenue is estimated to increase by $ 3.7297 thousands. 
B) For each increase of 1 thousand downloads, the expected revenue is estimated to increase by $ 3.7297 thousands. 
C) For each decrease of 1 thousand dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands. 
D) For each increase of 1 thousand dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands. 
A) For each decrease of 1 thousand downloads, the expected revenue is estimated to increase by $ 3.7297 thousands. 
B) For each increase of 1 thousand downloads, the expected revenue is estimated to increase by $ 3.7297 thousands. 
C) For each decrease of 1 thousand dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands. 
D) For each increase of 1 thousand dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands.

Question 3

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, there is no evidence of positive autocorrelation if the Durbin-Watson test statistic is found to be 1.78.

Accepted Answer

A) True 
 B)False

Question 4

SCENARIO 13-4 The managers of a brokerage firm are interested in finding out if the number of new clients a broker brings into the firm affects the sales generated by the broker.They sample 12 brokers and determine the number of new clients they have enrolled in the last year and their sales amounts in thousands of dollars.These data are presented in the table that follows.  
-Referring to Scenario 13-4, the standard error of the estimated slope coefficient is __________.

Accepted Answer

The answer of SCENARIO 13-4 The managers of a brokerage...

Question 5

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, the p-value of the measured t-test statistic to test whether the number of loan applications recorded affects the amount of time is _____.

Accepted Answer

The answer of SCENARIO 13-12 The manager of the purchasing...

Question 6

SCENARIO 13-3 The director of cooperative education at a state college wants to examine the effect of cooperative education job experience on marketability in the work place.She takes a random sample of 4 students.For these 4, she finds out how many times each had a cooperative education job and how many job offers they received upon graduation.These data are presented in the table below.  
-Referring to Scenario 13-3, the director of cooperative education wanted to test the hypothesis that the population slope was equal to 3.0.For a test with a level of significance of 0.05, the null hypothesis should be rejected if the value of the test statistic is ________.

Accepted Answer

The answer of SCENARIO 13-3 The director of cooperative education...

Question 7

The Durbin-Watson D statistic is used to check the assumption of normality.

Accepted Answer

A) True 
 B)False

Question 8

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, predict the amount of time it would take to process 150 loan applications.

Accepted Answer

The answer of SCENARIO 13-12 The manager of the purchasing...

Question 9

SCENARIO 13-4 The managers of a brokerage firm are interested in finding out if the number of new clients a broker brings into the firm affects the sales generated by the broker.They sample 12 brokers and determine the number of new clients they have enrolled in the last year and their sales amounts in thousands of dollars.These data are presented in the table that follows.  
-Referring to Scenario 13-4, the coefficient of determination is __________.

Accepted Answer

The answer of SCENARIO 13-4 The managers of a brokerage...

Question 10

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, what percentage of the variation in the amount of time needed can be explained by the variation in the number of loan applications processed?

Accepted Answer

The answer of SCENARIO 13-12 The manager of the purchasing...

Question 11

SCENARIO 13-13 In this era of tough economic conditions, voters increasingly ask the question: "Is the educational achievement level of students dependent on the amount of money the state in which they reside spends on education?" The partial computer output below is the result of using spending per student ($)as the independent variable and composite score which is the sum of the math, science and reading scores as the dependent variable on 35 states that participated in a study. The table includes only partial results.  
-Referring to Scenario 13-13, if the state decides to spend 1,000 dollar more per student, the estimated change in mean composite score is _________.

Accepted Answer

The answer of SCENARIO 13-13 In this era of tough...

Question 12

SCENARIO 13-10 The management of a chain electronic store would like to develop a model for predicting the weekly sales (in thousands of dollars)for individual stores based on the number of customers who made purchases.A random sample of 12 stores yields the following results:  
-Referring to Scenario 13-10, the mean weekly sales will increase by an estimated $0.01 for each additional purchasing customer.

Accepted Answer

A) True 
 B)False

Question 13

Rejection of the null hypothesis in a simple linear regression analysis can be interpreted as stating a cause and effect relationship between x and y.

Accepted Answer

A) True 
 B)False

Question 14

SCENARIO 13-1 A large national bank charges local companies for using their services.A bank official reported the results of a regression analysis designed to predict the bank's charges (Y)-- measured in dollars per month -- for services rendered to local companies.One independent variable used to predict service charges to a company is the company's sales revenue (X)-- measured in millions of dollars.Data for 21 companies who use the bank's services were used to fit the model:   The results of the simple linear regression are provided below.     two-tail p value =0.034 (for testing  
-Referring to Scenario 13-1, interpret the estimate of   the standard deviation of the random error term (standard error of the estimate)in the model.

Accepted Answer

A) About 95% of the observed service charges fall within $65 of the least squares line. 
B) About 95% of the observed service charges equal their corresponding predicted values. 
C) About 95% of the observed service charges fall within $130 of the least squares line. 
D) For every $1 million increase in sales revenue, we expect a service charge to increase $65. 
A) About 95% of the observed service charges fall within $65 of the least squares line. 
B) About 95% of the observed service charges equal their corresponding predicted values. 
C) About 95% of the observed service charges fall within $130 of the least squares line. 
D) For every $1 million increase in sales revenue, we expect a service charge to increase $65.

Question 15

Which of the following assumptions concerning the probability distribution of the random error term is stated incorrectly?

Accepted Answer

A) The distribution is normal. 
B) The mean of the distribution is 0. 
C) The variance of the distribution increases as X increases. 
D) The errors are independent. 
A) The distribution is normal. 
B) The mean of the distribution is 0. 
C) The variance of the distribution increases as X increases. 
D) The errors are independent.

Question 16

SCENARIO 13-10 The management of a chain electronic store would like to develop a model for predicting the weekly sales (in thousands of dollars)for individual stores based on the number of customers who made purchases.A random sample of 12 stores yields the following results:  
-Referring to Scenario 13-10, the value of the t test statistic and F test statistic should be the same when testing whether the number of customers who make purchases is a good predictor for weekly sales.

Accepted Answer

A) True 
 B)False

Question 17

SCENARIO 13-8 It is believed that GPA (grade point average, based on a four point scale)should have a positive linear relationship with ACT scores.Given below is the Excel output for predicting GPA using ACT scores based a data set of 8 randomly chosen students from a Big-Ten university.  
-Referring to Scenario 13-8, the interpretation of the coefficient of determination in this regression is

Accepted Answer

A) 57.74% of the total variation of ACT scores can be explained by GPA. 
B) ACT scores account for 57.74% of the total fluctuation in GPA. 
C) GPA accounts for 57.74% of the variability of ACT scores. 
D) None of the above. 
A) 57.74% of the total variation of ACT scores can be explained by GPA. 
B) ACT scores account for 57.74% of the total fluctuation in GPA. 
C) GPA accounts for 57.74% of the variability of ACT scores. 
D) None of the above.

Question 18

SCENARIO 13-4 The managers of a brokerage firm are interested in finding out if the number of new clients a broker brings into the firm affects the sales generated by the broker.They sample 12 brokers and determine the number of new clients they have enrolled in the last year and their sales amounts in thousands of dollars.These data are presented in the table that follows.  
-Referring to Scenario 13-4, the standard error of estimate is __________.

Accepted Answer

The answer of SCENARIO 13-4 The managers of a brokerage...

Question 19

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, what are the critical values of the Durbin-Watson test statistic using the 5% level of significance to test for evidence of positive autocorrelation?

Accepted Answer

The answer of SCENARIO 13-12 The manager of the purchasing...

Question 20

SCENARIO 13-12 The manager of the purchasing department of a large saving and loan organization would like to develop a model to predict the amount of time (measured in hours)it takes to record a loan application.Data are collected from a sample of 30 days, and the number of applications recorded and completion time in hours is recorded.Below is the regression output:      
-Referring to Scenario 13-12, the 90% confidence interval for the mean change in the amount of time needed as a result of recording one additional loan application is

Accepted Answer

A) wider than [0.1492, 0.6555]. 
B) narrower than [0.1492, 0.6555]. 
C) wider than [0.0109, 0.0143]. 
D) narrower than [0.0109, 0.0143]. 
A) wider than [0.1492, 0.6555]. 
B) narrower than [0.1492, 0.6555]. 
C) wider than [0.0109, 0.0143]. 
D) narrower than [0.0109, 0.0143].

The coefficient of determination tells you

The Durbin-Watson D statistic is used to check the assumption of normality.

Rejection of the null hypothesis in a simple linear regression analysis can be interpreted as stating a cause and effect relationship between x and y.

Which of the following assumptions concerning the probability distribution of the random error term is stated incorrectly?

Defining and Collecting Data

Organizing and Visualizing Variables

Numerical Descriptive Measures

Basic Probability

Discrete Probability Distributions

The Normal Distributions and Other Continuous Distributions

Sampling Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Two-Sample Tests

Analysis of Variance

Chi-Square and Nonparametric Tests

Introduction to Multiple Regression

Multiple Regression Model Building

Time-Series Forecasting

Business Analytics

A Roadmap for Analyzing Data

Statistical Applications in Quality Management Online

Decision Making Online

Understanding Statistics: Descriptive and Inferential Techniques

Filters

Exam 13: Simple Linear Regression

The coefficient of determination tells you

The Durbin-Watson D statistic is used to check the assumption of normality.

Rejection of the null hypothesis in a simple linear regression analysis can be interpreted as stating a cause and effect relationship between x and y.

Which of the following assumptions concerning the probability distribution of the random error term is stated incorrectly?

Defining and Collecting Data

Organizing and Visualizing Variables

Numerical Descriptive Measures

Basic Probability

Discrete Probability Distributions

The Normal Distributions and Other Continuous Distributions

Sampling Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Two-Sample Tests

Analysis of Variance

Chi-Square and Nonparametric Tests

Introduction to Multiple Regression

Multiple Regression Model Building

Time-Series Forecasting

Business Analytics

A Roadmap for Analyzing Data

Statistical Applications in Quality Management Online

Decision Making Online

Understanding Statistics: Descriptive and Inferential Techniques

Filters