Question 1151979
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<pre>

P(A | B)  actually means and is the same as  P(A &#8745; B)/P(B).


Therefore, the given  P(A | B) = 0.3855  means that  P(A &#8745; B)/P(B) = 0.385.


Multiplying both sides of the last equality by P(B), you get


    P(A &#8745; B) = 0.385*P(B) = 0.385*0.35 = 0.13475.


To find P(A U B), use the general formula


    P(A U B) = P(A) + P(B) - P(A &#8745; B) = 0.39 + 0.35 - 0.13475 = 0.60525.    


Last step,   P(B|A) = P(B &#8745; A) / P(A) = P(A &#8745; B) / P(A) = {{{0.13475/0.39}}} = 0.345513.
</pre>

Solved.  &nbsp;&nbsp;I answered all questions.


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