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P(A) = 0.50 P(B)= 0.80 P(A and B) = 0.20 . what is P(B\A)?

User Krumelur
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8.6k points

2 Answers

7 votes

Answer: P(B/A) = 0.40.

Step-by-step explanation: For any two events A and B, given that


P(A)=0.50,~~P(B)=0.80,~~P(A\cap B)=0.20.

We are to find the conditional probability of happening of event B given event A has already happened.

That is,


P(B/A)=?

From the formula for conditional probability, we have


P(B/A)=(P(B\cap A))/(P(A))\\\\\\\Rightarrow P(B/A)=(P(A\cap B))/(P(A))\\\\\\\Rightarrow P(B/A)=(0.20)/(0.50)\\\\\\\Rightarrow P(B/A)=0.40.

Thus, P(B/A) = 0.40.

User Wolmi
by
7.3k points
2 votes

Answer:

0.4

Explanation:

Use the formula for conditional probability.

P(B|A) = P(A&B)/P(A) = 0.20/0.50 = 0.4

User Ameer Moaaviah
by
9.5k points

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