SOLUTION: In Pennsylvania, 78% of all teenagers own an i-pod and 45% of all teenagers own an i-pod and a cell phone. What is the probability that a teenager owns a cell phone, given that t

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Question 1098894: In Pennsylvania, 78% of all teenagers own an i-pod and 45% of all teenagers own an i-pod and a cell phone. What is the probability that a teenager owns a cell phone, given that the teenager owns an i-pod.
Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
.
Let me re-formulate it equivalently in this simple form: 


    Of every 100 teenagers, 78 have an i-pod and 45 have both i-pod and sell phone.


Then it is absolutely clear that the probability under the question is   45%2F78.

The equivalent formula of the Probability theory is   P(A|B) = P%28A%29%2FP%28B%29 = 0.45%2F0.78.