76 Do you have a library card? According to a September 2008 Harris poll, 68% of all American adults have a public library card. The percentages do differ by gender—62% of males have library cards compared to 73% of females.

a. Consider the three probabilities: P1A2 = .68, P1AB2 = .62, and P1AC2 = .73. Define events A , B , and C .

b. Assuming that half of all American adults are males and half are females, what is the probability that an American adult is a female who owns a library card?