A young couple went to see a genetic counselor because each had a sibling affected with cystic fibrosis. (recessive disease, neither member of the couple is affected. Their four parents are also not affected))(a) What is the probability that the female of this couple is a carrier?(b) What are the chances that their child will be affected with cystic fibrosis?(c) What is the probability that their child will be a carrier of the cystic fibrosis mutation?

A: I would say a 50% chance that she's the carrier SF

B: 25%

C. The child will most likely be a carrier

Explanation: I'm not really sure if i'm correct but how I figured it out was. Mapping out the family tree and shading the circles if the had SF and if they did not have SF and was a carrier I only shaded half of it. After I finished shading everything out I made a punnet square to predict the probability of the child.    

David 1,988-1,956+32

It is David because when you find the unite ratio you get 1,988 for David and 1,956 for Megan.