Question

Calculate each probability

Answer 1

Complete question:

Calculate each probability given that P(A) = 0.2, P(B) = 0.8, and A & B are independent.

a) compute P(A and B)

b) If P(A|B) = 0.7, compute P(A and B).

Answer:

(a) P(A and B) = 0.16

(b) P(A and B) = 0.56

Step-by-step explanation:

Two events are independent if occurrence of one event does not affect possibility of occurrence of another.

(a) if A and B are independent, then P(A and B) = P(A) x P(B)

                                                                               = 0.2 x 0.8

                                                                               = 0.16

(b)  If P(A|B) = 0.7, compute P(A and B)

Considering the notations of independent events,

$P(A/B) = P(A)\\\\\frac{P(A \ and \ B)}{P(B)} = P(A)\\\\Thus, P(A/B) = \frac{P(A \ and \ B)}{P(B)}\\\\P(A \ and \ B) = P(A/B) *P(B)$

                     = 0.7 x 0.8

                     = 0.56