Question

Given that P(A)=0.8 and P(B|A)=0.31, find the joint probability P(A and B):

Answer 1

Answer: 0.248

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Work Shown:

P(A and B) = P(A)*P(B|A)

P(A and B) = 0.8*0.31

P(A and B) = 0.248

The notation P(B|A) means "Probability of B given A". It's the same as "P(B) given event A has happened". It is conditional probability notation. The symbol between the A and B is a vertical line and not a letter.