Chapter 9.1, Problem 4BSC

Using Confidence Intervals

a. Assume that we want to use a 0.05 significance level to test the claim that p₁ < p₂. Which is better: A hypothesis test or a confidence interval?

b. In general, when dealing with inferences for two population proportions, which two of the following are equivalent: confidence interval method; P-value method; critical value method?

c. If we want to use a 0.05 significance level to test the claim that p₁ < p₂, what confidence level should we use?

d. If we test the claim in part (c) using the sample data in Exercise 1, we get this confidence interval: −0.000508 < p₁ − p₂ < − 0.000309. What does this confidence interval suggest about the claim?