A high-risk group of 1083 male volunteers was included in a major clinical trial for testing a

Question:

A high-risk group of 1083 male volunteers was included in a major clinical trial for testing a new vaccine for type B hepatitis. The vaccine was given to 549 persons randomly selected from the group, and the others were injected with a neutral substance (placebo). Eleven of the vaccinated people and 70 of the non vaccinated ones later got the disease.
(a) Present these data in the following two-way frequency table.
(b) Compare the rates of incidence of hepatitis between the two subgroups.