In the spring of 2004, the U.S. Congress considered a bill that would prevent Americans from suing fast-food giants like McDonald’s for making them overweight. Although the fast-food industry may not be to blame, a study by Children’s Hospital in Boston reports that about two thirds of adult Americans and about 15% of children and adolescents are overweight. A random sample of 100 children is selected.

a. What is the probability that the sample percentage of overweight children exceeds 25%?

b. What is the probability that the sample percentage of overweight children is less than 12%?

c. Would it be unusual to find that 30% of the sampled children were overweight? Explain.