1. A comparison of the proportion of frequent binge drinkers, revisited. Refer to Exercise 8.46. Redo the exercise in terms of the proportion of nonfrequent binge drinkers in each classi?cation. Explain how you could have obtained these results from the calculations you did in Exercise 8.46.

2. Effects of reducing air pollution. A study that evaluated the effects of a reduction in exposure to traf?c-related air pollutants compared respiratory symptoms of 283 residents of an area with congested streets with 165 residents in a similar area where the congestion was removed because a bypass was constructed. The symptoms of the residents of both areas were evaluated at baseline and again a year after the bypass was completed.24 For the residents of the congested streets, 17 reported that their symptoms of wheezing improved between baseline and one year later, while 35 of the residents of the bypass streets reported improvement.

(a) Find the two sample proportions.

(b) Report the difference in the proportions and the standard error of the difference.

(c) What are the appropriate null and alternative