Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 15

Basic Computation: Confidence Interval for p 1 p 2 Consider two independent binomial experiments. In the first one, 40 trials had 10 successes. In the second one, 50 trials had 15 successes.
(a) Check Requirements Is it appropriate to use a normal distribution to approximate the
distribution Explain.
(b) Find a 90% confidence interval for p 1 p 2.
(c) Interpretation Based on the confidence interval you computed, can you be 90% confident that p 1 is less than p 2 Explain.