Question 430376
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The tutor @robertb has a great solution. I don't have much, if anything, to add really except for the fact that if A and B were independent, then,


P(A | B) = P(A)
P(B | A) = P(B)


Both must be true for A and B to be independent. We're told that P(B) = 0.30 and P(B | A) = 0.48 which contradicts the second equation shown above. 



Put another way: If A and B were independent, then either event would not alter the probability of the other. The notation P(B | A) indicates that we are given event A has happened. Saying P(B|A) = 0.48 is the same as saying "the probability event B happens is 0.48 given A has happened". But this is altered from P(B) = 0.30; therefore event A has changed the probability of event B's occurrence. Ultimately the two events are not independent.



All of this explanation applies to part A only
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