A First Course in Statistics, 12th Edition

Chapter 8

1. 8.1 large, independent samples

2. 8.3

   1. binomial

   2. normal

3. 8.5

   1. $.07\pm .067$

   2. $.06\pm .086$

   3. $-.15\pm .131$

4. 8.7 $z=1.16,$ fail to reject $H_0$

5. 8.9

   1. .55

   2. .70

   3. $-.15\pm .03$

   4. 90% confidence

   5. Dutch boys

6. 8.11

   1. 1. (1) all Indian hospital patients admitted in January,

      2. (2) all Indian hospital patients admitted in May

   2. .083

   3. (.033, .133)

   4. yes

7. 8.13

   1. b. $H_0:(p_1-p_2)=0,H_{\mathrm{a}}:(p_1-p_2)>0$

   2. c. $z=1.27$, fail to reject H₀

8. 8.15 no, $z=1.70$

9. 8.17 $z=8.34$, reject H₀

10. 8.19 yes; $z=2.13,$ reject $H_0$ at $\alpha =.05$

11. 8.21 $.48\pm .144$ ; proportion greater for those who slept

12. 8.23 Theory 1: $z=2.79$, reject $H_0$, support theory; Theory 2: $z=-.30$, fail to reject $H_0$, support theory

13. 8.27 $n_1=n_2=520$

14. 8.29

    1. $n_1=n_2=5051$

    2. impractical to obtain such a large sample

    3. difference almost meaningless

15. 8.31 $n_1=520,n_2=260$

16. 8.33 ...