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: P(A) = .68, P(A|B) = .62, and P(A|C) = .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?