1. Slide 4- 1 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Active Learning Lecture Slides For use with Classroom Response Systems Elementary Statistics: Picturing the World Fourth Edition by Larson and Farber Chapter 8: Hypothesis Testing with Two Samples

2. Slide 8- 2 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Classify the pair of samples as dependent or independent. Sample 1: Exam scores for 25 students in Dr. Smith’s morning statistics class. Sample 2: Exam scores for 28 students in Dr. Smith’s afternoon statistics class. A. Dependent B. Independent

3. Slide 8- 3 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Classify the pair of samples as dependent or independent. Sample 1: Exam scores for 25 students in Dr. Smith’s morning statistics class. Sample 2: Exam scores for 28 students in Dr. Smith’s afternoon statistics class. A. Dependent B. Independent

4. Slide 8- 4 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The mean cell phone bill for females (1) is higher than the mean cell phone for males (2). A. H 0 : μ 1 > μ 2 H a : μ 1 ≤ μ 2 B. H 0 : μ 1 < μ 2 H a : μ 1 ≥ μ 2 C. H 0 : μ 1 ≤ μ 2 H a : μ 1 > μ 2 D. H 0 : μ 1 ≥ μ 2 H a : μ 1 < μ 2

5. Slide 8- 5 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The mean cell phone bill for females (1) is higher than the mean cell phone for males (2). A. H 0 : μ 1 > μ 2 H a : μ 1 ≤ μ 2 B. H 0 : μ 1 < μ 2 H a : μ 1 ≥ μ 2 C. H 0 : μ 1 ≤ μ 2 H a : μ 1 > μ 2 D. H 0 : μ 1 ≥ μ 2 H a : μ 1 < μ 2

6. Slide 8- 6 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic z for the following situation: Claim: μ 1 = μ 2 ; s 1 = 3.7 n 1 = 40 s 2 = 2.1 n 2 = 35 A. z = 3.25 B. z = 3.36 C. z = 2.45 D. z = 5.89

7. Slide 8- 7 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic z for the following situation: Claim: μ 1 = μ 2 ; s 1 = 3.7 n 1 = 40 s 2 = 2.1 n 2 = 35 A. z = 3.25 B. z = 3.36 C. z = 2.45 D. z = 5.89

8. Slide 8- 8 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the pooled estimate of the standard deviation for the following situation: s 1 = 1.3 n 1 = 12 s 2 = 0.8 n 2 = 15 A. B. C. D.

9. Slide 8- 9 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the pooled estimate of the standard deviation for the following situation: s 1 = 1.3 n 1 = 12 s 2 = 0.8 n 2 = 15 A. B. C. D.

10. Slide 8- 10 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic t for the following situation (assume the populations are normally distributed and the population variances are equal): Claim: μ 1 = μ 2 ; s 1 = 1.3 n 1 = 12 s 2 = 0.8 n 2 = 15 A. t = –1.72 B. t = –1.63 C. t = –0.63 D. t = –0.69

11. Slide 8- 11 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic t for the following situation (assume the populations are normally distributed and the population variances are equal): Claim: μ 1 = μ 2 ; s 1 = 1.3 n 1 = 12 s 2 = 0.8 n 2 = 15 A. t = –1.72 B. t = –1.63 C. t = –0.69 D. t = –0.63

12. Slide 8- 12 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The mean score before and after a treatment are the same. A. H 0 : μ 1 = μ 2 H a : μ 1 ≠ μ 2 B. H 0 : μ 1 ≠ μ 2 H a : μ 1 = μ 2 C. H 0 : μ d = 0 H a : μ d ≠ 0 D. H 0 : μ d ≠ μ 2 H a : μ d = 0 Before758364 After544273

13. Slide 8- 13 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The mean score before and after a treatment are the same. A. H 0 : μ 1 = μ 2 H a : μ 1 ≠ μ 2 B. H 0 : μ 1 ≠ μ 2 H a : μ 1 = μ 2 C. H 0 : μ d = 0 H a : μ d ≠ 0 D. H 0 : μ d ≠ μ 2 H a : μ d = 0 Before758364 After544273

14. Slide 8- 14 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the mean of the difference between the paired data entries in the dependent samples, A. 4.17 B. 4.83 C. 1.33 D. 5.5 Before758364 After544273

15. Slide 8- 15 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the mean of the difference between the paired data entries in the dependent samples, A. 4.17 B. 4.83 C. 1.33 D. 5.5 Before758364 After544273

16. Slide 8- 16 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The proportion of female accountants (1) is less than the proportion of male accountants (2). A. H 0 : p 1 < p 2 H a : p 1 ≥ p 2 B. H 0 : p 1 ≤ p 2 H a : p 1 > p 2 C. H 0 : p 1 = p 2 H a : p 1 ≠ p 2 D. H 0 : p 1 ≥ p 2 H a : p 1 < p 2

17. Slide 8- 17 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley State the null and alternative hypotheses. The proportion of female accountants (1) is less than the proportion of male accountants (2). A. H 0 : p 1 < p 2 H a : p 1 ≥ p 2 B. H 0 : p 1 ≤ p 2 H a : p 1 > p 2 C. H 0 : p 1 = p 2 H a : p 1 ≠ p 2 D. H 0 : p 1 ≥ p 2 H a : p 1 < p 2

18. Slide 8- 18 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic z for the following situation: Claim: p 1 > p 2 ; x 1 = 100 n 1 = 250 x 2 = 90 n 2 = 300 A. z = 2.46 B. z = 1.45 C. z = 0.35 D. z = 3.37

19. Slide 8- 19 Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Find the standardized test statistic z for the following situation: Claim: p 1 > p 2 ; x 1 = 100 n 1 = 250 x 2 = 90 n 2 = 300 A. z = 2.46 B. z = 1.45 C. z = 0.35 D. z = 3.37