1. In a study by the United Dairy Industry Association, 42% of 655 persons age 35-44 said they seldom or never ate cottage cheese. For 455 individuals age 45-54, the corresponding percentage was 34%. At the 0.01 level, can we reject the possibility that the population percentages could be equal for these two groups? Source: United Dairy Industry Association, Cottage Cheese: Attitudes & Usage,p. 21.

2. During the course of a year, 38.0% of the 213 merchant ships lost were general cargo carriers, while 43.8% of the 219 ships lost during the following year were in this category. Using a two-tail test at the 0.05 level, examine whether this difference could have been the result of chance variation from one year to the next.

Source: Bureau of the Census, Statistical Abstract of the United States 1996, p. 657.