please help me with this question

that Pfizer's coronavirus vaccine had an efficacy & rate of 95 percent, the Food and Drug Administration approved the vaccine for Emergency Use. What is "efficacy," and how is it calculated? In this quesion, you will analyze the data from Pfizer's successful vaccine study to get a practical sense of how the vaccine performed. Infection Risk: The 43,661 subjects were split evenly between the placebo and vaccine groups (about 21,830 subjects per group). In the placebo group - the group that got a "fake" vaccine - 162 became infected with the coronavirus and showed symptoms. In the vaccine group - the group that got the real vaccine - that number was only eight. On a separate sheet of paper, draw the following table to store these numbers and our calculations: Group Group Size Number Infected Infection Risk If in U.S. Population Placebo 21,830 162 Vaccine 21,830 8