Sandy Irick is the public relations director for a large pharmaceutical fi rm that has been attacked in the popular press for distributing an allegedly unsafe vaccine. The vaccine protects against a virulent contagious disease that has a 0.04 probability of killing an infected person. Twenty-five percent of the population has been vaccinated.
A researcher has told her the following: The probability of any unvaccinated individual acquiring the disease is 0.30. Once vaccinated, the probability of acquiring the disease through normal means is zero. However, 2 percent of vaccinated people will show symptoms of the disease, and 3 percent of that group will die from it. Of people who are vaccinated and show no symptoms from the vaccination, 0.05 percent will die. Irick must draw some conclusions from these data for a staff meeting in 1 hour and a news conference later in the day.
- If a person is vaccinated, what is the probability of dying from the vaccine? If he was not vaccinated, what is the probability of dying?
- What is the probability of a randomly selected person dying from either the vaccine or the normally contracted disease?
Solution
