Health risks to beachgoers. According to a University of Florida veterinary researcher, the longer a beachgoer sits in wet sand or stays in the water, the higher the health risk

(University of Florida News, Jan. 29, 2008). Using data collected at 3 Florida beaches, the researcher discovered the following: (1) 6 out of 1,000 people exposed to wet sand for a 10-minute period will acquire gastroenteritis; (2) 12 out of 100 people exposed to wet sand for two consecutive hours will acquire gastroenteritis; (3) 7 out of 1,000 people exposed to ocean water for a 10-minute period will acquire gastroenteritis; and (4) 7 out of 100 people exposed to ocean water for a 70-minute period will acquire gastroenteritis.

a. If a beachgoer spends 10 minutes in the wet sand, what is the probability that he or she will acquire gastroenteritis?

b. If a beachgoer spends two hours in the wet sand, what is the probability that he or she will acquire gastroenteritis?

c. If a beachgoer spends 10 minutes in the ocean water, what is the probability that he or she will acquire gastroenteritis?

d. If a beachgoer spends 70 minutes in the ocean water, what is the probability that he or she will acquire gastroenteritis?