Slide 9- 1Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Active Learning Lecture Slides For use with Classroom Response Systems

Elementary Statistics Eleventh Edition

and the Triola Statistics Series

by Mario F. Triola

Chapter 9: Inferences from Two Samples

Slide 9- 2Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

A computer manufacturer randomly selects 2360 of its computers for quality assurance and finds that 2.54% of these computers are found to be defective. Find the number of successes x.

A. 63

B. 58

C. 65

D. 60

Slide 9- 3Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

A computer manufacturer randomly selects 2360 of its computers for quality assurance and finds that 2.54% of these computers are found to be defective. Find the number of successes x.

A. 63

B. 58

C. 65

D. 60

Slide 9- 4Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Compute the test statistic used to test the null hypothesis that p1 = p2: In a vote on the Clean Water bill, 41% of the 205 Democrats voted for the bill while 40% of the 230 Republicans voted for it.

A. 0.212

B. 0.127

C. 0.233

D. 0.180

Slide 9- 5Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Compute the test statistic used to test the null hypothesis that p1 = p2: In a vote on the Clean Water bill, 41% of the 205 Democrats voted for the bill while 40% of the 230 Republicans voted for it.

A. 0.212

B. 0.127

C. 0.233

D. 0.180

Slide 9- 6Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Determine whether the samples are independent or dependent: The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group who use a placebo drug.

A. Dependent samples

B. Independent samples

Slide 9- 7Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Determine whether the samples are independent or dependent: The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group who use a placebo drug.

A. Dependent samples

B. Independent samples

Slide 9- 8Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

The two data sets are dependent. Find d to the nearest tenth.

A. 0.6

B. 0.5

C. 0.7

D. 0.3

X 12.9 11.3 10.7 12.9 12.9

Y 12.6 12.6 10.0 10.7 12.3

Slide 9- 9Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

The two data sets are dependent. Find d to the nearest tenth.

A. 0.6

B. 0.5

C. 0.7

D. 0.3

X 12.9 11.3 10.7 12.9 12.9

Y 12.6 12.6 10.0 10.7 12.3

Slide 9- 10Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Assume you want to test the claim that the dependent sample data come from a population for which the mean difference is μd = 0. Compute the value of the t test statistic.

A. t = 2.8906

B. t = 1.292

C. t = 0.415

D. t = 0.578

X 11 5 13 5 9

Y 8 7 9 6 4

Slide 9- 11Copyright © 2010, 2007, 2004 Pearson Education, Inc. All Rights Reserved.

Assume you want to test the claim that the dependent sample data come from a population for which the mean difference is μd = 0. Compute the value of the t test statistic.

A. t = 2.8906

B. t = 1.292

C. t = 0.415

D. t = 0.578

X 11 5 13 5 9

Y 8 7 9 6 4