Question 1

Which is not true of the coefficient of determination?

Accepted Answer

A) It is the square of the coefficient of correlation. 
B) It is negative when there is an inverse relationship between X and Y. 
C) It reports the percentage of the variation in Y explained by X. 
D) It is calculated using sums of squares (e.g. ,SSR,SSE,SST). 
A) It is the square of the coefficient of correlation. 
B) It is negative when there is an inverse relationship between X and Y. 
C) It reports the percentage of the variation in Y explained by X. 
D) It is calculated using sums of squares (e.g. ,SSR,SSE,SST).

Question 2

Cause-and-effect direction between X and Y may be determined by running the regression twice and seeing whether Y = β0 + β1X or X = β1 + β0Y has the larger R2.

Accepted Answer

A) True 
 B)False

Question 3

The ordinary least squares method of estimation minimizes the estimated slope and intercept.

Accepted Answer

A) True 
 B)False

Question 4

The least squares regression line is obtained when the sum of the squared residuals is minimized.

Accepted Answer

A) True 
 B)False

Question 5

Bob thinks there is something wrong with Excel's fitted regression.What do you say?

Accepted Answer

A) The estimated equation is obviously incorrect. 
B) The R2 looks a little high but otherwise it looks OK. 
C) Bob needs to increase his sample size to decide. 
D) The relationship is linear,so the equation is credible. 
A) The estimated equation is obviously incorrect. 
B) The R2 looks a little high but otherwise it looks OK. 
C) Bob needs to increase his sample size to decide. 
D) The relationship is linear,so the equation is credible.

Question 6

In a simple bivariate regression with 60 observations,there will be ________ residuals.

Accepted Answer

A) 60 
B) 59 
C) 58 
D) 57 
A) 60 
B) 59 
C) 58 
D) 57

Question 7

Outliers can be detected by examining the standardized residuals.

Accepted Answer

A) True 
 B)False

Question 8

A researcher's 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.   What is the R2 for this regression?

Accepted Answer

A) .9018 
B) .0982 
C) .8395 
D) .1605 
A) .9018 
B) .0982 
C) .8395 
D) .1605

Question 9

The correlation coefficient r measures the strength of the linear relationship between two variables.

Accepted Answer

A) True 
 B)False

Question 10

Which statement is not correct?

Accepted Answer

A) Spurious correlation can often be reduced by expressing X and Y in per capita terms. 
B) Autocorrelation is mainly a concern when we are using time-series data. 
C) Heteroscedastic residuals will have roughly the same variance for any value of X. 
D) Standardized residuals make it easy to identify outliers or instances of poor fit. 
A) Spurious correlation can often be reduced by expressing X and Y in per capita terms. 
B) Autocorrelation is mainly a concern when we are using time-series data. 
C) Heteroscedastic residuals will have roughly the same variance for any value of X. 
D) Standardized residuals make it easy to identify outliers or instances of poor fit.

Question 11

The least squares regression line gives unbiased estimates of β0 and β1.

Accepted Answer

A) True 
 B)False

Question 12

In a sample of n = 40,a sample correlation of r = .400 provides sufficient evidence to conclude that the population correlation coefficient exceeds zero in a right-tailed test at

Accepted Answer

A) α = .025 but not α = .05. 
B) α = .05 but not α = .025. 
C) both α = .025 and α = .05. 
D) neither α = .025 nor α = .05. 
A) α = .025 but not α = .05. 
B) α = .05 but not α = .025. 
C) both α = .025 and α = .05. 
D) neither α = .025 nor α = .05.

Question 13

A fitted regression Profit = −570 + 30 Sales (all variables in thousands of dollars)was estimated from a random sample of 20 pharmacies.For a pharmacy with Sales = 10,we predict that Profit will be

Accepted Answer

A) 3570 
B) 2430 
C) −270 
D) 870 
A) 3570 
B) 2430 
C) −270 
D) 870

Question 14

Mary used a sample of 68 large U.S.cities to estimate the relationship between Crime (annual property crimes per 100,000 persons)and Income (median annual income per capita,in dollars).Her estimated regression equation was Crime = 428 + 0.050 Income.If Income decreases by 1000,we would expect that Crime will

Accepted Answer

A) increase by 428. 
B) decrease by 50. 
C) increase by 500. 
D) remain unchanged. 
A) increase by 428. 
B) decrease by 50. 
C) increase by 500. 
D) remain unchanged.

Question 15

In a sample of n = 20,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

Accepted Answer

A) ±.587 
B) ±.412 
C) ±.444 
D) ±.497 
A) ±.587 
B) ±.412 
C) ±.444 
D) ±.497

Question 16

Which is indicative of an inverse relationship between X and Y?

Accepted Answer

A) A negative F statistic 
B) A negative p-value for the correlation coefficient 
C) A negative correlation coefficient 
D) Either a negative F statistic or a negative p-value 
A) A negative F statistic 
B) A negative p-value for the correlation coefficient 
C) A negative correlation coefficient 
D) Either a negative F statistic or a negative p-value

Question 17

If R2 = .36 in the model Sales = 268 + 7.37 Ads with n = 50,the two-tailed test for correlation at α = .05 would say that there is a significant correlation between Sales and Ads.

Accepted Answer

A) True 
 B)False

Question 18

The ordinary least squares (OLS)method of estimation will minimize

Accepted Answer

A) neither the slope nor the intercept. 
B) only the slope. 
C) only the intercept. 
D) both the slope and intercept. 
A) neither the slope nor the intercept. 
B) only the slope. 
C) only the intercept. 
D) both the slope and intercept.

Question 19

In a sample of n = 23,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

Accepted Answer

A) ±.524 
B) ±.412 
C) ±.500 
D) ±.497 
A) ±.524 
B) ±.412 
C) ±.500 
D) ±.497

Question 20

A hypothesis test is conducted at the 5 percent level of significance to test whether the population correlation is zero.If the sample consists of 25 observations and the correlation coefficient is .60,what is the computed test statistic?

Accepted Answer

A) 2.071 
B) 1.960 
C) 3.597 
D) 1.645 
A) 2.071 
B) 1.960 
C) 3.597 
D) 1.645

Which is not true of the coefficient of determination?

Cause-and-effect direction between X and Y may be determined by running the regression twice and seeing whether Y = β0 + β1X or X = β1 + β0Y has the larger R2.

The ordinary least squares method of estimation minimizes the estimated slope and intercept.

The least squares regression line is obtained when the sum of the squared residuals is minimized.

Bob thinks there is something wrong with Excel's fitted regression.What do you say?

In a simple bivariate regression with 60 observations,there will be ________ residuals.

Outliers can be detected by examining the standardized residuals.

A researcher's 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. What is the R2 for this regression?

The correlation coefficient r measures the strength of the linear relationship between two variables.

Which statement is not correct?

The least squares regression line gives unbiased estimates of β0 and β1.

In a sample of n = 40,a sample correlation of r = .400 provides sufficient evidence to conclude that the population correlation coefficient exceeds zero in a right-tailed test at

A fitted regression Profit = −570 + 30 Sales (all variables in thousands of dollars)was estimated from a random sample of 20 pharmacies.For a pharmacy with Sales = 10,we predict that Profit will be

In a sample of n = 20,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

Which is indicative of an inverse relationship between X and Y?

If R2 = .36 in the model Sales = 268 + 7.37 Ads with n = 50,the two-tailed test for correlation at α = .05 would say that there is a significant correlation between Sales and Ads.

The ordinary least squares (OLS)method of estimation will minimize

In a sample of n = 23,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

A hypothesis test is conducted at the 5 percent level of significance to test whether the population correlation is zero.If the sample consists of 25 observations and the correlation coefficient is .60,what is the computed test statistic?

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

Which is not true of the coefficient of determination?

Cause-and-effect direction between X and Y may be determined by running the regression twice and seeing whether Y = β0 + β1X or X = β1 + β0Y has the larger R2.

The ordinary least squares method of estimation minimizes the estimated slope and intercept.

The least squares regression line is obtained when the sum of the squared residuals is minimized.

Bob thinks there is something wrong with Excel's fitted regression.What do you say?

In a simple bivariate regression with 60 observations,there will be ________ residuals.

Outliers can be detected by examining the standardized residuals.

A researcher's 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. What is the R2 for this regression?

The correlation coefficient r measures the strength of the linear relationship between two variables.

Which statement is not correct?

The least squares regression line gives unbiased estimates of β0 and β1.

In a sample of n = 40,a sample correlation of r = .400 provides sufficient evidence to conclude that the population correlation coefficient exceeds zero in a right-tailed test at

A fitted regression Profit = −570 + 30 Sales (all variables in thousands of dollars)was estimated from a random sample of 20 pharmacies.For a pharmacy with Sales = 10,we predict that Profit will be

In a sample of n = 20,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

Which is indicative of an inverse relationship between X and Y?

If R2 = .36 in the model Sales = 268 + 7.37 Ads with n = 50,the two-tailed test for correlation at α = .05 would say that there is a significant correlation between Sales and Ads.

The ordinary least squares (OLS)method of estimation will minimize

In a sample of n = 23,the critical value of the correlation coefficient for a two-tailed test at α = .05 is

A hypothesis test is conducted at the 5 percent level of significance to test whether the population correlation is zero.If the sample consists of 25 observations and the correlation coefficient is .60,what is the computed test statistic?

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