United Medicine, Inc., claims that a drug, Viro, significantly relieves the symptoms of a certain viral infection for 80 percent of all patients. Suppose that this drug is given to 13 randomly selected patients who have been diagnosed with the viral infection.

a. Let x equal the number of the 13 randomly selected patients whose symptoms are significantly relieved. What distribution describes the random variable x ? (Round your answers to 1 decimal place.)

b. Assuming that the company's claim is correct, find P(x 5). (Round your answer to 4 decimal places.)

c. Suppose that of the 13 randomly selected patients, 5 have had their symptoms significantly relieved by Viro. Based on the probability in part b, would you believe the claim of United Medicine, Inc.?