1. You have computed the following 95% confidence interval for a population mean u: [7.2, 9.2]. For the test of H0: u = 9.57 vs HA: u =/ 9.57, which of the following will be your decision at the 1% significance level.

A) Reject the null hypothesis

B) Do not reject the null hypothesis

C) More information is needed to make the decision.

Answer is C, but can you explain why?

2.

Suppose you are testing H₀: = 30 vs. H_a: 30 using a sample of size 50, and you have computed the value of the t-statistic: t = 2.0. Which of the following is true? Useful values: Z0.05=.645, Z0.025 =.96;

A)you can reject H₀ at the 5% level;

B) you cannot reject H₀ at the 5% level;

Explain why?

3. You have computed the following 90% confidence interval for a population proportion p: [0.3, 0.6]. For the test of H₀: p = 0.25 vs. H_a: p 0.25, which of the following will be your decision at the 5% significance level?

A) Reject the null hypothesis

B) Do not reject the null hypothesis

C) Reject the alternative hypothesis

D) Do not reject the alternative hypothesis

E) More information is needed to make the decision