Collecting data on traffic accident fatalities, the National Highway Traffic Safety Administration has found that 47.1% of the victims have 0.0% blood alcohol content (BAC), 7.0% of the victims have from 0.01 to 0.07% BAC, and 45.9% of the victims have at least 0.08% BAC. For a randomly selected victim:
a. What is the probability that the victim's BAC was at least 0.01%?
b. Given that the victim had been drinking prior to the accident, what is the probability that this victim's BAC was at least 0.08%?