Box 1 ( 7 black, 3 white balls)
Box 2 ( 4 black, 9 white balls)
Observe the boxes above.
Let:
1= choosing box 1,P(1)=0.4
2 = choosing box 2,P(2)=0.6a)
A trial has been performed and a black ball was obtained. What is the probability that the ball was from box 2? Explain your answer.