Question: In a clinical test of the drug Viagra, it was found that 4% of those in a placebo group experienced headaches.

a. Assuming that the same 4% rate applies to those taking Viagra, find the probability that among eight Viagra users, three experience headaches.

b. Assuming that the same 4% rate applies to those taking Viagra, find the probability that among eight randomly selected users of Viagra, all eight experienced a headache?

c. If all eight Viagra users were to experience a headache, would it appear that the headache rate for Viagra users is different from the 4% rate for those in the placebo group? Explain.