Jason knows that he is a carrier of CF. His wife, Julianne, has a brother with CF, which means the probability is 2/3 that she is a carrier. If Julianne is a carrier, each child she has with Jason has probability of 1/4 of having CF. If she is not a carrier, her children cannot have the disease. Jason and Julianne have one child, who does not have CF. This information reduces the probability that Julianne is a carrier. Use Bayes' rule to find the conditional probability that Julianne is a carrier, given that she and Jason have one child who does not have CF.