1. State the null and alternative hypotheses.
A company claims the mean lifetime of its AA batteries is more than 16 hours.
H0: μ > 16 Ha: μ ≤ 16
H0: μ < 16 Ha: μ ≥ 16
H0: μ ≤ 16 Ha: μ > 16
H0: μ ≥ 16 Ha: μ < 16

2. State the null and alternative hypotheses.
A company claims the mean lifetime of its AA batteries is more than 16 hours.
H0: μ > 16 Ha: μ ≤ 16
H0: μ < 16 Ha: μ ≥ 16
H0: μ ≤ 16 Ha: μ > 16
H0: μ ≥ 16 Ha: μ < 16

3. State the null and alternative hypotheses.
A student claims the mean cost of a textbook is at least $125.
H0: μ > Ha: μ ≤ 125
H0: μ < Ha: μ ≥ 125
H0: μ ≤ Ha: μ > 125
H0: μ ≥ Ha: μ < 125

4. State the null and alternative hypotheses.
A student claims the mean cost of a textbook is at least $125.
H0: μ > Ha: μ ≤ 125
H0: μ < Ha: μ ≥ 125
H0: μ ≤ Ha: μ > 125
H0: μ ≥ Ha: μ < 125

5. True or false:
Testing the claim that at least 88% of students have a cell phone would be a right-tail test.
True
False

6. True or false:
Testing the claim that at least 88% of students have a cell phone would be a right-tail test.
True
False

7. You are testing the claim that the mean cost of a new car is more than $25,200. How should you interpret a decision that rejects the null hypothesis?
There is enough evidence to reject the claim.
There is enough evidence to support the claim.
There is not enough evidence to reject the claim.
There is not enough evidence to support the claim.

8. You are testing the claim that the mean cost of a new car is more than $25,200. How should you interpret a decision that rejects the null hypothesis?
There is enough evidence to reject the claim.
There is enough evidence to support the claim.
There is not enough evidence to reject the claim.
There is not enough evidence to support the claim.

9. True or false:
Given H0: μ = 40 Ha: μ ≠ 40 and P = You would reject the null hypothesis at the 0.05 level of significance.
True
False

10. True or false:
Given H0: μ = 40 Ha: μ ≠ 40 and P = You would reject the null hypothesis at the 0.05 level of significance.
True
False

11. Find the critical value, z0, for a left-tailed test at the 0
Find the critical value, z0, for a left-tailed test at the 0.10 level of significance.
z0 = –1.645
z0 = 1.645
z0 = –1.28
z0 = 1.28

12. Find the critical value, z0, for a left-tailed test at the 0
Find the critical value, z0, for a left-tailed test at the 0.10 level of significance.
z0 = –1.645
z0 = 1.645
z0 = –1.28
z0 = 1.28

13. Find the standardized test statistic z for the following situation:
Claim: μ >15; s = n = 40
z = 2.60
z = –2.60
z = –0.07
z = 12.90

14. Find the standardized test statistic z for the following situation:
Claim: μ >15; s = n = 40
z = 2.60
z = –2.60
z = –0.07
z = 12.90

15. Find the critical value(s), t0, for a two-tailed test, α = 0
Find the critical value(s), t0, for a two-tailed test, α = 0.05, and n = 8.
–t0 = –1.96 and t0 = 1.96
–t0 = –2.306 and t0 = 2.306
–t0 = –1.895 and t0 = 1.895
–t0 = – and t0 = 2.365

16. Find the critical value(s), t0, for a two-tailed test, α = 0
Find the critical value(s), t0, for a two-tailed test, α = 0.05, and n = 8.
–t0 = –1.96 and t0 = 1.96
–t0 = –2.306 and t0 = 2.306
–t0 = –1.895 and t0 = 1.895
–t0 = – and t0 = 2.365