SOLUTION: Question: You ask your roommate to mail a letter for you. Suppose there is a 0.17 probability your roommate will forget to mail it. Should your roommate mail your letter, there is

Algebra ->  Probability-and-statistics -> SOLUTION: Question: You ask your roommate to mail a letter for you. Suppose there is a 0.17 probability your roommate will forget to mail it. Should your roommate mail your letter, there is       Log On


   



Question 909034: Question: You ask your roommate to mail a letter for you. Suppose there is a 0.17 probability your roommate will forget to mail it. Should your roommate mail your letter, there is a 0.91 probability that Canada Post will deliver the letter. If the letter is never delivered, what is the probability your roommate mailed the letter?
Thank you!

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
P(A|B) = P(A and B)/P(B)
P(not delivered|mailed) = P(mailed and not delivered) /P(mailed) = .09/.83