Consider the following.

Question

P(A) = 0.31 and P(B) = 0.41, and P(A and B) = 0.1271

(a) What is P(A | B)? (Give your answer correct to two decimal places.)

(b) What is P(B | A)? (Give your answer correct to two decimal places.)

(c) Are A and B independent?
yes no cannot be determined

Answer 1

(a)
P(A|B) conditional probability of A given B
=P(A∩B)/P(B) [∩ written as & c a p ; omit the spaces]

(b)
P(B|A)
=P(B∩A)/P(A)

(c) A and B are independent if and only if P(A∩B)=P(A)*P(B)