Question 1

For a regression with 200 observations,we expect that about 10 residuals will exceed two standard errors.

Accepted Answer

A) True 
 B)False

Question 2

Find the sample correlation coefficient for the following data.

Accepted Answer

A) .8911 
B) .9124 
C) .9822 
D) .9556 
A) .8911 
B) .9124 
C) .9822 
D) .9556

Question 3

If n = 15 and r = .4296,the corresponding t statistic to test for zero correlation is

Accepted Answer

A) 1.715 
B) 7.862 
C) 2.048 
D) impossible to determine without α. 
A) 1.715 
B) 7.862 
C) 2.048 
D) impossible to determine without α.

Question 4

When homoscedasticity exists,we would expect that a plot of the residuals versus the fitted Y

Accepted Answer

A) will form approximately a straight line. 
B) crosses the centerline too many times. 
C) will yield a Durbin-Watson statistic near 2. 
D) will show no pattern at all. 
A) will form approximately a straight line. 
B) crosses the centerline too many times. 
C) will yield a Durbin-Watson statistic near 2. 
D) will show no pattern at all.

Question 5

A trend line has been fitted to a company's annual sales.The fitted trend is yt = 50 + 5 xt,where t is the time index (t = 1,2,... ,n)and yt is annual sales (in millions of dollars).What is the forecast for period 13?

Accepted Answer

A) $125 million 
B) $50 million. 
C) $97 million 
D) $115 million 
A) $125 million 
B) $50 million. 
C) $97 million 
D) $115 million

Question 6

A scatter plot is used to visualize the association (or lack of association)between two quantitative variables.

Accepted Answer

A) True 
 B)False

Question 7

Using the least squares formulas,the regression line must pass through the origin.

Accepted Answer

A) True 
 B)False

Question 8

Find the slope of the simple regression of Y on X.

Accepted Answer

A) 1.833 
B) 3.294 
C) 0.762 
D) −2.228 
A) 1.833 
B) 3.294 
C) 0.762 
D) −2.228

Question 9

Using a two-tailed test at α = .05 for n = 30,we would reject the hypothesis of zero correlation if the absolute value of r exceeds

Accepted Answer

A) .2992. 
B) .3609. 
C) .0250. 
D) .2004. 
A) .2992. 
B) .3609. 
C) .0250. 
D) .2004.

Question 10

If R2 = .36 in the model Sales = 268 + 7.37 Ads,then Ads explains 36 percent of the variation in Sales.

Accepted Answer

A) True 
 B)False

Question 11

In correlation analysis,neither X nor Y is designated as the independent variable.

Accepted Answer

A) True 
 B)False

Question 12

In a simple bivariate regression with 25 observations,which statement is most nearly correct?

Accepted Answer

A) A nonstandardized residual whose value is ei = 4.22 would be considered an outlier. 
B) A leverage statistic of 0.16 or more would indicate high leverage. 
C) Standardizing the residuals will eliminate any heteroscedasticity. 
D) Nonnormal residuals imply biased coefficient estimates,a major problem. 
A) A nonstandardized residual whose value is ei = 4.22 would be considered an outlier. 
B) A leverage statistic of 0.16 or more would indicate high leverage. 
C) Standardizing the residuals will eliminate any heteroscedasticity. 
D) Nonnormal residuals imply biased coefficient estimates,a major problem.

Question 13

When the errors in a regression model are not independent,the regression model is said to have autocorrelation.

Accepted Answer

A) True 
 B)False

Question 14

Mary noticed that old coins are smoother and more worn.She weighed 31 nickels and recorded their ages,and then performed a simple regression to estimate the model Weight = β0 + β1 Age,where weight is the weight of the coin in grams and Age is the age of the coin in years.Her results are shown below.Write a brief analysis of these results,using what you have learned in this chapter.Make a prediction of Weight when Age = 10 and also when Age = 20.What does this tell you? Is the intercept meaningful in this regression?

Accepted Answer

It is reasonable to postulate that a cau

Question 15

A simple decimal transformation often improves data conditioning.

Accepted Answer

A) True 
 B)False

Question 16

In a simple bivariate regression,Fcalc = tcalc2.

Accepted Answer

A) True 
 B)False

Question 17

If the residuals violate the assumption of autocorrelation,we know that they

Accepted Answer

A) are probably outliers. 
B) are not independent. 
C) have constant variance. 
D) are normally distributed. 
A) are probably outliers. 
B) are not independent. 
C) have constant variance. 
D) are normally distributed.

Question 18

A variable transformation in a regression (e.g. ,replacing Y with log(Y))

Accepted Answer

A) may reduce heteroscedasticity. 
B) changes the model specification. 
C) makes the model easier to interpret. 
D) leads to severe autocorrelation. 
A) may reduce heteroscedasticity. 
B) changes the model specification. 
C) makes the model easier to interpret. 
D) leads to severe autocorrelation.

Question 19

A researcher's Excel results are shown below using Femlab (labor force participation rate among females)to try to predict Cancer (death rate per 100,000 population due to cancer)in the 50 U.S.states.     Which of the following statements is not true?

Accepted Answer

A) The standard error is too high for this model to be of any predictive use. 
B) The 95 percent confidence interval for the coefficient of Femlab is -4.29 to -0.28. 
C) Significant correlation exists between Femlab and Cancer at α = .05. 
D) The two-tailed p-value for Femlab will be less than .05. 
A) The standard error is too high for this model to be of any predictive use. 
B) The 95 percent confidence interval for the coefficient of Femlab is -4.29 to -0.28. 
C) Significant correlation exists between Femlab and Cancer at α = .05. 
D) The two-tailed p-value for Femlab will be less than .05.

Question 20

A poor prediction (large residual)indicates an observation with high leverage.

Accepted Answer

A) True 
 B)False

For a regression with 200 observations,we expect that about 10 residuals will exceed two standard errors.

Find the sample correlation coefficient for the following data.

If n = 15 and r = .4296,the corresponding t statistic to test for zero correlation is

When homoscedasticity exists,we would expect that a plot of the residuals versus the fitted Y

A trend line has been fitted to a company's annual sales.The fitted trend is yt = 50 + 5 xt,where t is the time index (t = 1,2,... ,n)and yt is annual sales (in millions of dollars).What is the forecast for period 13?

A scatter plot is used to visualize the association (or lack of association)between two quantitative variables.

Using the least squares formulas,the regression line must pass through the origin.

Find the slope of the simple regression of Y on X.

Using a two-tailed test at α = .05 for n = 30,we would reject the hypothesis of zero correlation if the absolute value of r exceeds

If R2 = .36 in the model Sales = 268 + 7.37 Ads,then Ads explains 36 percent of the variation in Sales.

In correlation analysis,neither X nor Y is designated as the independent variable.

In a simple bivariate regression with 25 observations,which statement is most nearly correct?

When the errors in a regression model are not independent,the regression model is said to have autocorrelation.

A simple decimal transformation often improves data conditioning.

In a simple bivariate regression,Fcalc = tcalc2.

If the residuals violate the assumption of autocorrelation,we know that they

A variable transformation in a regression (e.g. ,replacing Y with log(Y))

A researcher's Excel results are shown below using Femlab (labor force participation rate among females)to try to predict Cancer (death rate per 100,000 population due to cancer)in the 50 U.S.states. Which of the following statements is not true?

A poor prediction (large residual)indicates an observation with high leverage.

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

For a regression with 200 observations,we expect that about 10 residuals will exceed two standard errors.

Find the sample correlation coefficient for the following data.

If n = 15 and r = .4296,the corresponding t statistic to test for zero correlation is

When homoscedasticity exists,we would expect that a plot of the residuals versus the fitted Y

A trend line has been fitted to a company's annual sales.The fitted trend is yt = 50 + 5 xt,where t is the time index (t = 1,2,... ,n)and yt is annual sales (in millions of dollars).What is the forecast for period 13?

A scatter plot is used to visualize the association (or lack of association)between two quantitative variables.

Using the least squares formulas,the regression line must pass through the origin.

Find the slope of the simple regression of Y on X.

Using a two-tailed test at α = .05 for n = 30,we would reject the hypothesis of zero correlation if the absolute value of r exceeds

If R2 = .36 in the model Sales = 268 + 7.37 Ads,then Ads explains 36 percent of the variation in Sales.

In correlation analysis,neither X nor Y is designated as the independent variable.

In a simple bivariate regression with 25 observations,which statement is most nearly correct?

When the errors in a regression model are not independent,the regression model is said to have autocorrelation.

A simple decimal transformation often improves data conditioning.

In a simple bivariate regression,Fcalc = tcalc2.

If the residuals violate the assumption of autocorrelation,we know that they

A variable transformation in a regression (e.g. ,replacing Y with log(Y))

A researcher's Excel results are shown below using Femlab (labor force participation rate among females)to try to predict Cancer (death rate per 100,000 population due to cancer)in the 50 U.S.states. Which of the following statements is not true?

A poor prediction (large residual)indicates an observation with high leverage.

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