Question

If events X and Y are independent, what must be true? Check all that apply.

Answer 1

All these are true when X and Y are independent events:

1) The occurrence or lack of event X does not influence the occurrence of event Y, and the occurrence  or lack of event Y does not influence the occurrence of event X.

2) P(X∩Y) = P(X) * P(Y)

3) P(X | Y) = P(X).... this is the probability of X given Y is equal to the probability of X.

4) P (Y | X) = P(Y)

5) P(A∪B) = P(A) + P(B) - P(A∩B)

Answer 2

3. P(Y | X) = P(Y) and 6. P(X | Y) = P(X)