]> Answers to Selected Exercises

Answers to Selected Exercises

9. Hypothesis Testing

  1. Tests in the Normal Model
  2. Tests in the Bernoulli Model
  3. Tests in the Two Sample Normal Model
  4. Chi-Square Tests

2. Tests in the Normal Model

2.43.

  1. Test statistic 3.33, critical values 1.645 . Reject
  2. P 0.0010
  3. The power of the test at 10.05 is approximately 0.0509.
  4. Sample size 223

2.44.

  1. Test statistic 3.464 , critical value 1.665 . Reject
  2. P 0.0001 so reject

2.45.

  1. Test statistic 2.828, critical value 1.2988. Reject
  2. P 0.0071 so reject

2.46.

  1. Test statistic 2.0, critical value 2.363. Fail to reject
  2. P 0.0001 so reject

2.47. Test statistic 1 , critical value 2.328 . Fail to reject

2.48. Test statistic 15.49, critical value 2.6270. Reject

2.49. Test statistic 1.269 , critical value 1.7017 . Fail to reject

2.50. Test statistic 3.730 , critical value 1.6748 . Reject

2.51.

  1. Test statistic 1.563 , critical values 1.672 . Fail to reject
  2. Test statistic 4.556, critical value 1.2988. Reject
  3. Test statistic 1.028 , critical value 1.2988 Fail to Reject

3. Tests in the Bernoulli Model

3.9. Test statistic 1.743, critical value 1.282. Reject

3.10. Test statistic 1.743, critical values 1.961 . Reject ; The coin is almost certainly unfair.

3.11. Test statistic 1.333 , critical value 1.645 . Fail to reject .

3.12. Test statistic 0.707, critical value 1.282. Fail to reject .

3.13.

  1. Test statistic 0.162, critical values 1.645 Fail to reject .
  2. Test statistic 4.117 , critical value 1.282 Reject .
  3. Test statistic 8.266, critical value 1.282. Reject .

3.19. Test statistic 3.286, critical value 1.282. Reject .

3.20.

  1. Test statistic 3.394, critical values 1.645 Reject .
  2. Test statistic 1.980 , critical value 1.282 Reject .
  3. Test statistic 0.566 , critical value 1.282 . Fail to reject .

4. Tests in the Two-Sample Normal Model

4.15.

  1. Test statistic 0.4, critical values 0.585, 1.667. Reject .
  2. Test statistic 1.0, critical values 1.6625 . Fail to reject .
  3. Probably not

4.16. Test statistic 2.8, critical value 1.3184. Reject .

4.17.

  1. Test statistic 1.1, critical values 0.6227, 1.6072. Fail to reject .
  2. Test statistic 11.4 , critical value 1.6602 . Reject .

4.18.

  1. Test statistic 0.56, critical values 0.7175, 1.3942. Reject .
  2. Test statistic 4.97 , critical values 1.645 . Reject .

6. Chi-Square Tests

6.15. 1 degree of freedom, V 1 , P 0.3173 .

6.16.

  1. 3 degree of freedom, V 11.78 , P 0.008 .
  2. 2 degree of freedom, V 2.301 , P 0.316 .

6.17.

  1. 5 degree of freedom, V 5.383 , P 0.371 .
  2. 5 degree of freedom, V 18.45 , P 0.002 .

6.18.

  1. 10 degree of freedom, V 6.2 , P 0.798 .
  2. 5 degree of freedom, V 7.103 , P 0.213 .

6.19. 1 degree of freedom, V 4.332 , P 0.037 .

6.20. We use the following partition of : 0 1 2 3 4 8 9 10 .

  1. 7 degrees of freedom, V 11.321 , P 0.125 .
  2. 6 degrees of freedom, V 8.141 , P 0.228 .

6.21. 3 degrees of freedom, V 70.111 , P 0 .

6.22. Using the following partition of : 750 750 775 775 800 800 825 825 850 850 875 875 900 900 925 925 950 950 975 975 . we have 8 degrees of freedom, V 11.443 , P 0.178 .