9.14 Potency of an Antibiotic A drug manufac- turer claimed that the mean potency of one of its antibi- otics was 80%. A random sample of n = 100 capsules were tested and produced a sample mean of x=79.7%, with a standard deviation of s = 0.8%. Do the data present sufficient evidence to refute the manufacturer's claim? Let a 0.05.

a. State the null hypothesis to be tested.

b. State the alternative hypothesis.

c. Conduct a statistical test of the null hypothesis and state your conclusion.