Chapter 8.5, Problem 8.61LM

Assuming that n₁ =  n₂, find the sample sizes needed to estimate (p₁ − p₂) for each of the following situations:

1. a. Sampling error = .01 with 99% confidence. Assume that p₁ ≈ .4 and p₂ ≈ .7.
2. b. A 90% confidence interval of width .05. Assume that there is no prior information available to obtain approximate values of p₁ and p₂.
3. c. Sampling error = .03 with 90% confidence. Assume that p₁ ≈ .2 and p₂ ≈ .3.