Slide 7- 1 Copyright © 2010 Pearson Education, Inc. Active Learning Lecture Slides For use with Classroom Response Systems Business Statistics First Edition by Sharpe, De Veaux, Velleman Chapter 7: Scatterplots, Association, and Correlation

Slide 7- 2 Copyright © 2010 Pearson Education, Inc. In a scatterplot, the explanatory variable is placed on the ____________ axis. A. x B. y

Slide 7- 3 Copyright © 2010 Pearson Education, Inc. In a scatterplot, the explanatory variable is placed on the ____________ axis. A. x B. y

Slide 7- 4 Copyright © 2010 Pearson Education, Inc. Which of the following conditions does not need to be checked when using correlation? A. Quantitative variables condition B. Linearity condition C. Normal condition D. Outlier condition

Slide 7- 5 Copyright © 2010 Pearson Education, Inc. Which of the following conditions does not need to be checked when using correlation? A. Quantitative variables condition B. Linearity condition C. Normal condition D. Outlier condition

Slide 7- 6 Copyright © 2010 Pearson Education, Inc. All but one of the following statements contain a mistake. Which one could be true? A. The correlation between height and weight is inches per pound. B. The correlation between height and weight is C. The correlation between the breed of a dog and its weight is D. The correlation between gender and age is

Slide 7- 7 Copyright © 2010 Pearson Education, Inc. All but one of the following statements contain a mistake. Which one could be true? A. The correlation between height and weight is inches per pound. B. The correlation between height and weight is C. The correlation between the breed of a dog and its weight is D. The correlation between gender and age is

Slide 7- 8 Copyright © 2010 Pearson Education, Inc. A correlation of zero between two quantitative variables means that A. we have done something wrong in our calculation of r. B. there is no association between the two variables. C. there is no linear association between the two variables. D. re-expressing the data will guarantee a linear association between the two variables.

Slide 7- 9 Copyright © 2010 Pearson Education, Inc. A correlation of zero between two quantitative variables means that A. we have done something wrong in our calculation of r. B. there is no association between the two variables. C. there is no linear association between the two variables. D. re-expressing the data will guarantee a linear association between the two variables.

Slide Copyright © 2010 Pearson Education, Inc. It takes a while for new employees to master a complex assembly. The correlation between time an employee has been on the job and the time it takes to complete this assembly is most likely to be A. exactly B. near C. near 0. D. near +0.6.

Slide Copyright © 2010 Pearson Education, Inc. It takes a while for new employees to master a complex assembly. The correlation between time an employee has been on the job and the time it takes to complete this assembly is most likely to be A. exactly B. near C. near 0. D. near +0.6.

Slide Copyright © 2010 Pearson Education, Inc. For families who live in apartments, the correlation between household income and the amount of rent paid is r = Which is true? I. In general, families with higher incomes pay more in rent. II. On average, families spend 60% of their income on rent. III. In general, families with higher incomes pay less in rent. A. I only B. II only C. I and III only D. I, II, and III

Slide Copyright © 2010 Pearson Education, Inc. For families who live in apartments, the correlation between household income and the amount of rent paid is r = Which is true? I. In general, families with higher incomes pay more in rent. II. On average, families spend 60% of their income on rent. III. In general, families with higher incomes pay less in rent. A. I only B. II only C. I and III only D. I, II, and III

Slide Copyright © 2010 Pearson Education, Inc. A hidden variable that stands behind a relationship and determines it by simultaneously affecting the other two variables is called a ______ variable. A. lurking B. causal C. response D. predictor

Slide Copyright © 2010 Pearson Education, Inc. A hidden variable that stands behind a relationship and determines it by simultaneously affecting the other two variables is called a ______ variable. A. lurking B. causal C. response D. predictor

Slide Copyright © 2010 Pearson Education, Inc. A positive correlation (r =.65) was found between ice tea consumption and the frequency of bee stings. Which of the following is the best explanation? A. People who drink a lot of ice tea are more likely to be stung by bees than people who dont. B. Drinking ice tea attracts bees and results in more bee sting cases. C. Summer is probably a lurking variable. People drink more ice tea in the summer and bee stings are also more prevalent then. D. Drinking tea is the causal variable.

Slide Copyright © 2010 Pearson Education, Inc. A positive correlation (r =.65) was found between ice tea consumption and the frequency of bee stings. Which of the following is the best explanation? A. People who drink a lot of ice tea are more likely to be stung by bees than people who dont. B. Drinking ice tea attracts bees and results in more bee sting cases. C. Summer is probably a lurking variable. People drink more ice tea in the summer and bee stings are also more prevalent then. D. Drinking tea is the causal variable.

Slide Copyright © 2010 Pearson Education, Inc. Once we have a strong correlation, we can conclude that the explanatory variable caused the effect. A. True B. False

Slide Copyright © 2010 Pearson Education, Inc. Once we have a strong correlation, we can conclude that the explanatory variable caused the effect. A. True B. False

Slide Copyright © 2010 Pearson Education, Inc. Testing revealed a slight positive correlation (r =.30) between creative ability and analytical skills for a sample of college students. Suppose an individual who scored extraordinarily high on both was added to the sample. We would expect A. the correlation to become negative because of the addition of this outlier. B. the correlation to be near zero because of the addition of this outlier. C. the correlation to be stronger in the positive direction because of the addition of this outlier. D. the correlation to remain unchanged.

Slide Copyright © 2010 Pearson Education, Inc. Testing revealed a slight positive correlation (r =.30) between creative ability and analytical skills for a sample of college students. Suppose an individual who scored extraordinarily high on both was added to the sample. We would expect A. the correlation to become negative because of the addition of this outlier. B. the correlation to be near zero because of the addition of this outlier. C. the correlation to be stronger in the positive direction because of the addition of this outlier. D. the correlation to remain unchanged.