Exam 13: Linear Regression and Correlation

A random sample of 15 homes that recently sold is obtained.The correlation between the area of the home,in square feet,and the selling price is 0.40.We want to test the null hypothesis that the correlation in the population is less than or equal to zero versus the alternate that it is greater than zero.The rejection region will fall in the ________ tail of a t distribution.

(Short Answer)

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Question 21

Trying to predict weekly sales with a standard error of estimate of $1,955,we would conclude that 68 percent of the predictions would not be off more than $1,955,95 percent would not be off by more $3,910,and 99.7 percent would not be off by more than $5,865.

(True/False)

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Question 22

How is the coefficient of determination related to the correlation coefficient? ________

(Short Answer)

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Question 23

The least squares principle is used to determine the best-fitting line.

(True/False)

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Question 24

If the coefficient of correlation is -0.90,the coefficient of determination is -0.81.

(True/False)

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Question 25

Pearson's coefficient of correlation can be used if the data is nominally scaled.

(True/False)

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Question 26

If the value of r is -0.96,what does this indicate about the dependent variable as the independent variable increases? ___________

(Short Answer)

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Question 27

The regression equation is used to estimate a value of the dependent variable Y based on a selected value of the independent variable X.

(True/False)

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Question 28

Which of the following is true about the standard error of estimate?

(Multiple Choice)

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Question 29

If we are studying the relationship between high school grade point average (GPA)and college GPA,and want to predict college GPA,what kind of variable is high school GPA? ________________

(Short Answer)

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Question 30

If the correlation between two variables is close to one,the association is

(Multiple Choice)

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Question 31

A regression equation is a mathematical equation that defines the relationship between two variables.

(True/False)

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Question 32

If the dependent variable is in dollars,the standard error is in what units? ______________

(Short Answer)

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Question 33

A mathematical transformation can be used to change a curvilinear relationship between two variables to a linear relationship.

(True/False)

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Question 34

In regression analysis,we expect prediction error or ( - Y)does not equal zero.

(True/False)

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Question 35

An economist is interested in predicting the unemployment rate based on gross domestic product.Since the economist is interested in predicting unemployment,the independent variable is gross domestic product.

(True/False)

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Question 36

When testing the strength of the relationship between two variables,the null hypothesis is:

(True/False)

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Question 37

A chart that shows the relationship between a dependent variable and an independent variable is called a _______________________.

(Short Answer)

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Question 38

A sales manager for an advertising agency believes there is a relationship between the number of contacts and the amount of the sales.To verify this belief,the following data was collected: The 95% confidence interval for 30 calls is

(Multiple Choice)

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Question 39

Which of the following is NOT a difference between a confidence interval and a prediction interval?

(Multiple Choice)

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Question 40

Showing 21 - 40 of 135

Trying to predict weekly sales with a standard error of estimate of $1,955,we would conclude that 68 percent of the predictions would not be off more than $1,955,95 percent would not be off by more $3,910,and 99.7 percent would not be off by more than $5,865.

How is the coefficient of determination related to the correlation coefficient? ________

The least squares principle is used to determine the best-fitting line.

If the coefficient of correlation is -0.90,the coefficient of determination is -0.81.

Pearson's coefficient of correlation can be used if the data is nominally scaled.

If the value of r is -0.96,what does this indicate about the dependent variable as the independent variable increases? ___________

The regression equation is used to estimate a value of the dependent variable Y based on a selected value of the independent variable X.

Which of the following is true about the standard error of estimate?

If we are studying the relationship between high school grade point average (GPA)and college GPA,and want to predict college GPA,what kind of variable is high school GPA? ________________

If the correlation between two variables is close to one,the association is

A regression equation is a mathematical equation that defines the relationship between two variables.

If the dependent variable is in dollars,the standard error is in what units? ______________

A mathematical transformation can be used to change a curvilinear relationship between two variables to a linear relationship.

In regression analysis,we expect prediction error or ( - Y)does not equal zero.

An economist is interested in predicting the unemployment rate based on gross domestic product.Since the economist is interested in predicting unemployment,the independent variable is gross domestic product.

When testing the strength of the relationship between two variables,the null hypothesis is:

A chart that shows the relationship between a dependent variable and an independent variable is called a _______________________.

A sales manager for an advertising agency believes there is a relationship between the number of contacts and the amount of the sales.To verify this belief,the following data was collected: The 95% confidence interval for 30 calls is

Which of the following is NOT a difference between a confidence interval and a prediction interval?

What Is Statistics

Describing Data: Frequency Distributions and Graphic Presentations

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Methods and the Central Limit Theorem

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Multiple Regression and Correlation Analysis

Chi-Square Applications

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