The American Heart Association is about to conduct an anti-smoking campaign and wants to know the fraction of Americans over 40 who smoke. a. Suppose a sample of 1089 Americans over 40 is drawn. Of these people, 806 don't smoke. Using the data, estimate the proportion of Americans over 40 who smoke. Enter your answer as a fraction or a decimal number rounded to three decimal places.
b. Suppose a sample of 861 Americans over 47 is drawn. Of these people, 577 don't smoke. Using the data, construct the 80% confidence interval for the population proportion of Americans over 47 who smoke. Round your answers to three decimal places.