Bayes Theorem Problems
1. A class consists of 60% men and 40% women.† Of the men, 25% are blond, while 45% of the women are blond. If a student is chosen at random and is found to be blond, what is the probability that student is a man?
2. It is known in a certain country that 20% of mothers use spanking as a method of disciplining their children.† 85% of the mothers that spank their children use valium, while 25% of mothers that donít use spanking use valium.† Does this data suggest that valium causes mothers to spank their children?† Explain.
3.† Two different suppliers, A and B, provide a manufacturer with the same part.† All supplies of this part are kept in a large bin.† in the past, 5% of the parts supplied by A and 9% of the parts supplied by B have been defective.† A supplies four times as many parts as B.† Suppose you reach into the bin and select a part, and find it is nondefective.† What is the probability that it was supplied by A?