Question 1

Outliers can be detected by examining the standardized residuals.

Accepted Answer

A) True 
 B)False

Question 2

In a simple regression, there are n - 2 degrees of freedom associated with the error sum of squares (SSE).

Accepted Answer

A) True 
 B)False

Question 3

There are usually several possible regression lines that will minimize the sum of squared errors.

Accepted Answer

A) True 
 B)False

Question 4

The sample coefficient of correlation does not have which property?

Accepted Answer

A) It can range from -1.00 up to +1.00. 
B) It is also sometimes called Pearson's r. 
C) It is tested for significance using a t-test. 
D) It assumes that Y is the dependent variable. 
A) It can range from -1.00 up to +1.00. 
B) It is also sometimes called Pearson's r. 
C) It is tested for significance using a t-test. 
D) It assumes that Y is the dependent variable.

Question 5

Which is correct to find the value of the coefficient of determination (R2)?

Accepted Answer

A) SSR/SSE 
B) SSR/SST 
C) 1 - SST/SSE 
A) SSR/SSE 
B) SSR/SST 
C) 1 - SST/SSE

Question 6

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 7

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

Accepted Answer

A) True 
 B)False

Question 8

An observation with high leverage will have a large residual (usually an outlier).

Accepted Answer

A) True 
 B)False

Question 9

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 10

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

Accepted Answer

A) True 
 B)False

Question 11

The slope of a proposed population regression model yS1U1B1iS1U1B0 = ?S1U1B10 S1U1B0+ ?S1U1B11S1U1B0 xS1U1B1i S1U1B0+ ?S1U1B1iS1U1B0 is assumed to be:

Accepted Answer

A) a random variable. 
B) distributed normally. 
C) a statistic. 
D) a parameter. 
A) a random variable. 
B) distributed normally. 
C) a statistic. 
D) a parameter.

Question 12

In the population model yi = β0 + β1 x + ε, the βj are:

Accepted Answer

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

Question 13

In simple linear regression, the p-value of the slope will always equal the p-value of the F statistic.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

Find the sample correlation coefficient for the following data. $$\begin{array} { | c | c | } 
\hline X & Y \
\hline 3 & 9 \
\hline 5 & 13 \
\hline 9 & 10 \
\hline 13 & 23 \
\hline 15 & 35 \
\hline
\end{array}$$

Accepted Answer

A) .7291 
B) .8736 
C) .9118 
D) .9563 
A) .7291 
B) .8736 
C) .9118 
D) .9563

Question 16

A sample correlation r = .40 indicates a stronger linear relationship than r = -.60.

Accepted Answer

A) True 
 B)False

Question 17

A news network stated that a study had found a positive correlation between the number of children a worker has and his or her earnings last year. You may conclude that:

Accepted Answer

A) people should have more children so they can get better jobs. 
B) the data are erroneous because the correlation should be negative. 
C) causation is in serious doubt. 
D) statisticians have small families. 
A) people should have more children so they can get better jobs. 
B) the data are erroneous because the correlation should be negative. 
C) causation is in serious doubt. 
D) statisticians have small families.

Question 18

In a sample of size n = 36, a sample correlation of r = -.450 provides sufficient evidence to conclude that the population correlation coefficient differs significantly from zero in a two-tailed test at:

Accepted Answer

A) α = .01 
B) α = .05 
C) both α = .01 and α = .05. 
D) neither α = .01 nor α = .05. 
A) α = .01 
B) α = .05 
C) both α = .01 and α = .05. 
D) neither α = .01 nor α = .05.

Question 19

Which is not an assumption of least squares regression?

Accepted Answer

A) Normal X values 
B) Non-autocorrelated errors 
C) Homoscedastic errors 
D) Normal errors 
A) Normal X values 
B) Non-autocorrelated errors 
C) Homoscedastic errors 
D) Normal errors

Question 20

The standard error of the regression:

Accepted Answer

A) is based on squared deviations from the regression line. 
B) may assume negative values if b1 < 0. 
C) is in squared units of the dependent variable. 
D) may be cut in half to get an approximate 95 percent prediction interval. 
A) is based on squared deviations from the regression line. 
B) may assume negative values if b1 < 0. 
C) is in squared units of the dependent variable. 
D) may be cut in half to get an approximate 95 percent prediction interval.

Outliers can be detected by examining the standardized residuals.

In a simple regression, there are n - 2 degrees of freedom associated with the error sum of squares (SSE).

There are usually several possible regression lines that will minimize the sum of squared errors.

The sample coefficient of correlation does not have which property?

Which is correct to find the value of the coefficient of determination (R²)?

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

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

An observation with high leverage will have a large residual (usually an outlier).

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

The slope of a proposed population regression model y_i = ?₀+ ?₁ x_i+ ?_i is assumed to be:

In the population model y_i = β₀ + β₁ x + ε, the β_j are:

In simple linear regression, the p-value of the slope will always equal the p-value of the F statistic.

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

Find the sample correlation coefficient for the following data. X Y 3 9 5 13 9 10 13 23 15 35

A sample correlation r = .40 indicates a stronger linear relationship than r = -.60.

A news network stated that a study had found a positive correlation between the number of children a worker has and his or her earnings last year. You may conclude that:

In a sample of size n = 36, a sample correlation of r = -.450 provides sufficient evidence to conclude that the population correlation coefficient differs significantly from zero in a two-tailed test at:

Which is not an assumption of least squares regression?

The standard error of the regression:

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

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 12: Simple Regression

Outliers can be detected by examining the standardized residuals.

In a simple regression, there are n - 2 degrees of freedom associated with the error sum of squares (SSE).

There are usually several possible regression lines that will minimize the sum of squared errors.

The sample coefficient of correlation does not have which property?

Which is correct to find the value of the coefficient of determination (R2)?

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

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

An observation with high leverage will have a large residual (usually an outlier).

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

The slope of a proposed population regression model yi = ?0 + ?1 xi + ?i is assumed to be:

In the population model yi = β0 + β1 x + ε, the βj are:

In simple linear regression, the p-value of the slope will always equal the p-value of the F statistic.

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

Find the sample correlation coefficient for the following data. X Y 3 9 5 13 9 10 13 23 15 35

A sample correlation r = .40 indicates a stronger linear relationship than r = -.60.

A news network stated that a study had found a positive correlation between the number of children a worker has and his or her earnings last year. You may conclude that:

In a sample of size n = 36, a sample correlation of r = -.450 provides sufficient evidence to conclude that the population correlation coefficient differs significantly from zero in a two-tailed test at:

Which is not an assumption of least squares regression?

The standard error of the regression:

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

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Which is correct to find the value of the coefficient of determination (R²)?

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 slope of a proposed population regression model y_i = ?₀+ ?₁ x_i+ ?_i is assumed to be:

In the population model y_i = β₀ + β₁ x + ε, the β_j are: