A random sample of college students found that 13 of them had gotten a flu shot at the beginning of the winter and 28 had not. These data are shown in the accompanying table.
Bottom line is that getting a flu shot probably helps.
After two weeks the mites were removed and all plants were inoculated with Verticillium, a fungus that causes wilt disease. The accompanying table shows the numbers of plants that developed symptoms of wilt disease. Let p 1 be the probability that a plant infected with the Mites treatment develops Wilt disease, and let p 2 be the probability that a plant not infected with the Mites treatment develops Wilt disease. Each woman was asked whether she used oral contraceptives. The data for the 155 pairs are displayed in the table below.