Question 1

Given that the sum of squares for error is 60 and the sum of squares for regression is 140, then what is the value of the coefficient of determination?

Accepted Answer

A)  0.300 
B)  0.429 
C)  0.700 
D)  0.837 
A)  0.300 
B)  0.429 
C)  0.700 
D)  0.837

Question 2

The normal probability plot is a graph that plots the residuals against the expected value of that residual if it had come from a normal distribution. When the residuals are normally distributed or approximately so, the plot should appear as a straight line, sloping upward at a   angle.

Accepted Answer

A) True 
 B)False

Question 3

When all the points in a scatter diagram lie precisely on the estimated regression line, the sample coefficient of correlation will show the variables to be perfectly correlated.

Accepted Answer

A) True 
 B)False

Question 4

If all the points in a scatterplot lie on the least-squares regression line, then the correlation coefficient must be 1.0.

Accepted Answer

A) True 
 B)False

Question 5

Which of these coefficients of correlation (r) indicates a strong positive linear relationship between the two variables of interest?

Accepted Answer

A)  -1.3 
B)  -0.9 
C)  0.8 
D)  0.9 
A)  -1.3 
B)  -0.9 
C)  0.8 
D)  0.9

Question 6

Which of the following statements is NOT a property of the residuals in simple linear regression model?

Accepted Answer

A)  They sum to 0. 
B)  They have a mean of 0..
C They have a median of 0 
C)  They have a standard deviation of 1. 
A)  They sum to 0. 
B)  They have a mean of 0..
C They have a median of 0 
C)  They have a standard deviation of 1.

Question 7

The vertical spread of the data points about the regression line is measured by the y-intercept.

Accepted Answer

A) True 
 B)False

Question 8

Which of these coefficients of correlation (r) indicates a strong negative linear relationship between the two variables of interest?

Accepted Answer

A)  -1.3 
B)  -0.9 
C)  0.8 
D)  0.9 
A)  -1.3 
B)  -0.9 
C)  0.8 
D)  0.9

Question 9

If the correlation coefficient between two variables is very close to 0, this means that there is no relationship between the two variables.

Accepted Answer

A) True 
 B)False

Question 10

In the simple linear regression model, what does the slope represent?

Accepted Answer

A)  the value of y when x = 0 
B)  the average change in y per unit change in x 
C)  the value of x when y = 0 
D)  the average change in x per unit change in y 
A)  the value of y when x = 0 
B)  the average change in y per unit change in x 
C)  the value of x when y = 0 
D)  the average change in x per unit change in y

Question 11

Which value of the coefficient of correlation r indicates a stronger correlation than 0.65?

Accepted Answer

A)  0.60 
B)  0.55 
C)  -0.45 
D)  -0.75 
A)  0.60 
B)  0.55 
C)  -0.45 
D)  -0.75

Question 12

In a simple linear regression , if the sum of squares for regression is 90, then the sum of squares for error is at most 90.

Accepted Answer

A) True 
 B)False

Question 13

In a simple linear regression , if the coefficient of determination is 0.95, this means that 95% of the variation in the independent variable x can be explained by regression line.

Accepted Answer

A) True 
 B)False

Question 14

In a simple linear regression including n = 10 observations, which of the following critical values would be appropriate for a 95% confidence interval estimation for the average value of y?

Accepted Answer

A)  1.860 
B)  2.228 
C)  2.262 
D)  2.306 
A)  1.860 
B)  2.228 
C)  2.262 
D)  2.306

Question 15

The standard error of the estimate in a simple linear regression model measures the variation in the slope coefficient from sample to sample.

Accepted Answer

A) True 
 B)False

Question 16

What does the least-squares method for determining the best fit minimize?

Accepted Answer

A)  total variation in the dependent variable 
B)  sum of squares for error 
C)  sum of squares for regression 
D)  total variation in the independent variable 
A)  total variation in the dependent variable 
B)  sum of squares for error 
C)  sum of squares for regression 
D)  total variation in the independent variable

Question 17

The value of the sum of squares for regression can never be larger than the value of sum of squares for error.

Accepted Answer

A) True 
 B)False

Question 18

If a least-squares regression line has a y-intercept of 6.84 and a slope of 2.16, then when x = 1 the actual value of y must be 9.

Accepted Answer

A) True 
 B)False

Question 19

If the correlation coefficient for two variables is found to be 0.094, then the scatterplot will show the data upward sloping from lower left to upper right.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following is NOT an assumption for the simple linear regression model?

Accepted Answer

A)  The distribution of the error terms will be skewed to left or right, depending on the values of the dependent variable. 
B)  The error terms have equal variances for all values of the independent variable. 
C)  The error terms are independent of each other. 
D)  The mean of the dependent variable for all levels of the independent variable can be connected by a straight line. 
A)  The distribution of the error terms will be skewed to left or right, depending on the values of the dependent variable. 
B)  The error terms have equal variances for all values of the independent variable. 
C)  The error terms are independent of each other. 
D)  The mean of the dependent variable for all levels of the independent variable can be connected by a straight line.

Exam 12: A: linear Regression and Correlation

Given that the sum of squares for error is 60 and the sum of squares for regression is 140, then what is the value of the coefficient of determination?

The normal probability plot is a graph that plots the residuals against the expected value of that residual if it had come from a normal distribution. When the residuals are normally distributed or approximately so, the plot should appear as a straight line, sloping upward at a angle.

When all the points in a scatter diagram lie precisely on the estimated regression line, the sample coefficient of correlation will show the variables to be perfectly correlated.

If all the points in a scatterplot lie on the least-squares regression line, then the correlation coefficient must be 1.0.

Which of these coefficients of correlation (r) indicates a strong positive linear relationship between the two variables of interest?

Which of the following statements is NOT a property of the residuals in simple linear regression model?

The vertical spread of the data points about the regression line is measured by the y-intercept.

Which of these coefficients of correlation (r) indicates a strong negative linear relationship between the two variables of interest?

If the correlation coefficient between two variables is very close to 0, this means that there is no relationship between the two variables.

In the simple linear regression model, what does the slope represent?

Which value of the coefficient of correlation r indicates a stronger correlation than 0.65?

In a simple linear regression , if the sum of squares for regression is 90, then the sum of squares for error is at most 90.

In a simple linear regression , if the coefficient of determination is 0.95, this means that 95% of the variation in the independent variable x can be explained by regression line.

In a simple linear regression including n = 10 observations, which of the following critical values would be appropriate for a 95% confidence interval estimation for the average value of y?

The standard error of the estimate in a simple linear regression model measures the variation in the slope coefficient from sample to sample.

What does the least-squares method for determining the best fit minimize?

The value of the sum of squares for regression can never be larger than the value of sum of squares for error.

If a least-squares regression line has a y-intercept of 6.84 and a slope of 2.16, then when x = 1 the actual value of y must be 9.

If the correlation coefficient for two variables is found to be 0.094, then the scatterplot will show the data upward sloping from lower left to upper right.

Which of the following is NOT an assumption for the simple linear regression model?

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

A: probability and Probability Distributions

B: probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Estimation

A: large-Sample Tests of Hypotheses

B: large-Sample Tests of Hypotheses

A: Inference From Small Samples

B: Inference From Small Samples

A: The Analysis of Variance

B: The Analysis of Variance

B: linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

A:nonparametric Statistics

B:nonparametric Statistics

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