Question 1

In a simple regression,the F statistic is calculated by taking the ratio of MSR to the MSE.

Accepted Answer

A) True 
 B)False

Question 2

Autocorrelated errors are not usually a concern for regression models using cross-sectional data.

Accepted Answer

A) True 
 B)False

Question 3

The coefficient of determination is the percentage of the total variation in the response variable Y that is explained by the predictor X.

Accepted Answer

A) True 
 B)False

Question 4

A fitted regression for an exam in Prof.Hardtack's class showed Score = 20 + 7 Study,where Score is the student's exam score and Study is the student's study hours.The regression yielded R2 = 0.50 and SE = 8.Bob studied 9 hours.The quick 95 percent prediction interval for Bob's grade is approximately

Accepted Answer

A) 69 to 97 
B) 75 to 91 
C) 67 to 99 
D) 76 to 90 
A) 69 to 97 
B) 75 to 91 
C) 67 to 99 
D) 76 to 90

Question 5

Omission of a relevant predictor is a common source of model misspecification.

Accepted Answer

A) True 
 B)False

Question 6

If the residuals violate the assumption of normality,we expect that

Accepted Answer

A) the sample was not taken randomly. 
B) the residuals will not sum to zero. 
C) least squares formulas will fail. 
D) confidence intervals may be unreliable. 
A) the sample was not taken randomly. 
B) the residuals will not sum to zero. 
C) least squares formulas will fail. 
D) confidence intervals may be unreliable.

Question 7

If the residuals from a fitted regression violate the assumption of homoscedasticity,we know that

Accepted Answer

A) they are normally distributed. 
B) they are independent of one another. 
C) their variance is not constant. 
D) there are extreme outliers. 
A) they are normally distributed. 
B) they are independent of one another. 
C) their variance is not constant. 
D) there are extreme outliers.

Question 8

High leverage for an observation indicates that X is far from its mean.

Accepted Answer

A) True 
 B)False

Question 9

Which is not an assumed characteristic of εi in the population model yi = β0 + β1 xi + εi?

Accepted Answer

A) It is a random variable. 
B) It has zero mean. 
C) It is a statistic. 
D) It is unobservable. 
A) It is a random variable. 
B) It has zero mean. 
C) It is a statistic. 
D) It is unobservable.

Question 10

If the fitted regression is Y = 3.5 + 2.1X (R2 = .25,n = 25),it is incorrect to conclude that

Accepted Answer

A) Y increases 2.1 percent for a 1 percent increase in X. 
B) the estimated regression line crosses the Y axis at 3.5. 
C) the sample correlation coefficient must be positive. 
D) the value of the sample correlation coefficient is .50. 
A) Y increases 2.1 percent for a 1 percent increase in X. 
B) the estimated regression line crosses the Y axis at 3.5. 
C) the sample correlation coefficient must be positive. 
D) the value of the sample correlation coefficient is .50.

Question 11

A common source of spurious correlation between X and Y is when a third unspecified variable Z affects both X and Y.

Accepted Answer

A) True 
 B)False

Question 12

In a simple regression,which would suggest a significant relationship between X and Y?

Accepted Answer

A) Large p-value for the estimated slope 
B) Large t statistic for the slope 
C) Large p-value for the F statistic 
D) Small t statistic for the slope 
A) Large p-value for the estimated slope 
B) Large t statistic for the slope 
C) Large p-value for the F statistic 
D) Small t statistic for the slope

Question 13

A researcher's regression results are shown below using n = 8 observations.   Which is the 95 percent confidence interval for the slope?

Accepted Answer

A) [1.333,2.284] 
B) [1.602,2.064] 
C) [1.268,2.398] 
D) [1.118,2.449] 
A) [1.333,2.284] 
B) [1.602,2.064] 
C) [1.268,2.398] 
D) [1.118,2.449]

Question 14

The larger the absolute value of the t statistic of the slope in a simple linear regression,the stronger the linear relationship that exists between X and Y.

Accepted Answer

A) True 
 B)False

Question 15

To calculate a residual for the ith observation,we do not need the

Accepted Answer

A) actual value of yi. 
B) estimated slope. 
C) standard error. 
D) estimated intercept. 
A) actual value of yi. 
B) estimated slope. 
C) standard error. 
D) estimated intercept.

Question 16

Ill-conditioned refers to a variable whose units are too large or too small .

Accepted Answer

A) True 
 B)False

Question 17

Confidence intervals for predicted Y are less precise when the residuals are very small.

Accepted Answer

A) True 
 B)False

Question 18

In the population model yi = β0 + β1 xi + εi the βj are

Accepted Answer

A) parameters. 
B) statistics. 
C) estimated. 
D) observable. 
A) parameters. 
B) statistics. 
C) estimated. 
D) observable.

Question 19

A local trucking company fitted a regression to relate the cost of its shipments as a function of the distance traveled.The Excel fitted regression is shown.   Based on this estimated relationship,when distance increases by 50 miles,the expected shipping cost would increase by how much?

Accepted Answer

A) $286 
B) $143 
C) $104 
D) $301 
A) $286 
B) $143 
C) $104 
D) $301

Question 20

A local trucking company fitted a regression to relate the travel time (days)of its shipments as a function of the distance traveled (miles).The fitted regression is Time = −7.126 + .0214 Distance,based on a sample of 20 shipments.The estimated standard error of the slope is 0.0053.Find the critical value for a right-tailed test to see if the slope is positive,using α = .05.

Accepted Answer

A) 2.101 
B) 2.552 
C) 1.960 
D) 1.734 
A) 2.101 
B) 2.552 
C) 1.960 
D) 1.734

In a simple regression,the F statistic is calculated by taking the ratio of MSR to the MSE.

Autocorrelated errors are not usually a concern for regression models using cross-sectional data.

The coefficient of determination is the percentage of the total variation in the response variable Y that is explained by the predictor X.

Omission of a relevant predictor is a common source of model misspecification.

If the residuals violate the assumption of normality,we expect that

If the residuals from a fitted regression violate the assumption of homoscedasticity,we know that

High leverage for an observation indicates that X is far from its mean.

Which is not an assumed characteristic of εi in the population model yi = β0 + β1 xi + εi?

If the fitted regression is Y = 3.5 + 2.1X (R2 = .25,n = 25),it is incorrect to conclude that

A common source of spurious correlation between X and Y is when a third unspecified variable Z affects both X and Y.

In a simple regression,which would suggest a significant relationship between X and Y?

A researcher's regression results are shown below using n = 8 observations. Which is the 95 percent confidence interval for the slope?

The larger the absolute value of the t statistic of the slope in a simple linear regression,the stronger the linear relationship that exists between X and Y.

To calculate a residual for the ith observation,we do not need the

Ill-conditioned refers to a variable whose units are too large or too small .

Confidence intervals for predicted Y are less precise when the residuals are very small.

In the population model yi = β0 + β1 xi + εi the βj are

A local trucking company fitted a regression to relate the cost of its shipments as a function of the distance traveled.The Excel fitted regression is shown. Based on this estimated relationship,when distance increases by 50 miles,the expected shipping cost would increase by how much?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Multiple Regression

Chi-Square Tests

Filters

Exam 12: Simple Regression

In a simple regression,the F statistic is calculated by taking the ratio of MSR to the MSE.

Autocorrelated errors are not usually a concern for regression models using cross-sectional data.

The coefficient of determination is the percentage of the total variation in the response variable Y that is explained by the predictor X.

Omission of a relevant predictor is a common source of model misspecification.

If the residuals violate the assumption of normality,we expect that

If the residuals from a fitted regression violate the assumption of homoscedasticity,we know that

High leverage for an observation indicates that X is far from its mean.

Which is not an assumed characteristic of εi in the population model yi = β0 + β1 xi + εi?

If the fitted regression is Y = 3.5 + 2.1X (R2 = .25,n = 25),it is incorrect to conclude that

A common source of spurious correlation between X and Y is when a third unspecified variable Z affects both X and Y.

In a simple regression,which would suggest a significant relationship between X and Y?

A researcher's regression results are shown below using n = 8 observations. Which is the 95 percent confidence interval for the slope?

The larger the absolute value of the t statistic of the slope in a simple linear regression,the stronger the linear relationship that exists between X and Y.

To calculate a residual for the ith observation,we do not need the

Ill-conditioned refers to a variable whose units are too large or too small .

Confidence intervals for predicted Y are less precise when the residuals are very small.

In the population model yi = β0 + β1 xi + εi the βj are

A local trucking company fitted a regression to relate the cost of its shipments as a function of the distance traveled.The Excel fitted regression is shown. Based on this estimated relationship,when distance increases by 50 miles,the expected shipping cost would increase by how much?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Multiple Regression

Chi-Square Tests

Filters