Unformatted text preview: own a dog? Answer. Let D be the families that own a dog, and C the families that own a cat. We are given P ( D ) = . 36 , P ( C ) = . 30 , P ( C | D ) = . 22 We want to know P ( D | C ). We know P ( D | C ) = P ( D ∩ C ) / P ( C ). To ﬁnd the numerator, we use P ( D ∩ C ) = P ( C | D ) P ( D ) = ( . 22)( . 36) = . 0792. So P ( D | C ) = . 0792 /. 3 = . 264 = 26 . 4%. An example: Suppose 30% of the women in a class received an A on the test and 25% of the men received an A. The class is 60% women. Given that a person chosen at random received an A, what is the probability this person is a women? Answer. Let A be the event of receiving an A, W be the event of being a woman, and M the event of being a man. We are given P ( A | W ) = 21...
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- Spring '10
- Probability, Probability theory, Neutering, Theobromine poisoning, Cosmopolitan species