Large Sample Tests for a Population Mean

Answers

1. 

a. Z \leq-1.645
b. Z \leq-1.96 or Z \geq 1.96
c. Z \geq 1.28
d. Z \leq-1.645 or Z \geq 1.645

3. 

a. Z \leq-0.84
b. Z \leq-1.645
c. Z \leq-1.96 or Z \geq 1.96
d. Z \geq 3.1

5. 

a. Z=2.235
b. Z=2.592
c. Z=-2.122
d. Z=3.002

7. 

a. Z=-2.18,-z_{0.10}=-1.28, reject H_{0}.
b. Z=1.61, z_{0.05}=1.645, do not reject H_{0}.
c. Z=-4.47,-z_{0.01}=-2.33, reject H_{0}.

9. Z=-2.86,-z_{0.01}=-2.33, reject H_{0}.

11. Z=-1.69,-z_{0.025}=-1.96, do not reject H_{0}.

13. Z=8.33, z_{0.05}=1.645, reject H_{0}.

15. Z=.2.02, z_{0.10}=1.28, reject H_{0}.

17. Z=-2.08,-z_{0.01}=-2.33, do not reject H_{0}.

19. 

a. Z=2.54, z_{0.05}=1.645, reject H_{0};
b. Z=2.54, z_{0.10}=1.28, reject H_{0}.

21. H_{0}: \mu=1510 vs. H_{a}: \mu > 1510. Test Statistic: Z=2.7882. Rejection Region: [2.33, \infty). Decision: Reject H_{0}

23. 

a. \mu_{0}=1528.74
b. H_{0}: \mu=1510 vs. H_{a}: \mu > 1510. Test Statistic: Z=-1.41. Rejection Region: [1.28, \infty). Decision: Fail to reject H_{0}.
c. No, it is a Type II error.