Flu vaccine A drug company has developed a new vaccine for preventing the flu. The company claims that fewer than 5% of adults who use its vaccine will get the flu. To test the claim, researchers give the vaccine to a random sample of 1000 adults. Of these, 43 get the flu.

(a) Do these data provide convincing evidence to support the company’s claim?

(b) Which kind of mistake—a Type I error or a Type II error—could you have made in (a)? Explain.

(c) From the company’s point of view, would a Type I error or Type II error be more serious? Why?