Question

Suppose that we have a sample space S = {E1, E2, E3, E4, E5, E6, E7}, where E1, E2, . . . , E7 denote the sample points. The following probability assignments apply:
P(E1) = .05, P(E2) = .20, P(E3) = .20, P(E4) = .25, P(E5) = .15, P(E6) = .10, and P(E7) = .05.

Let A = {E1, E4, E6} B = {E2, E4, E7} C = {E2, E3, E5, E7}

Find the probability of the intersection of A and B.

Answer 1

Answer:

The required probability for the intersection of A & B = 0.25

Step-by-step explanation:

Given that:

Sample space S =  {E1, E2, E3, E4, E5, E6, E7} and the probability of each sample points are:

P(E1) = .05, P(E2) = .20, P(E3) = .20, P(E4) = .25, P(E5) = .15, P(E6) = .10, and P(E7) = .05.

Also;

A = {E1, E4, E6}

B = {E2, E4, E7}

C = {E2, E3, E5, E7}

Then

P(A) = 0.05 + 0.25 + 0.10 = 0.4

P(B) = 0.20 + 0.25 + 0.05 = 0.5

P(C) = 0.20 + 0.20 + 0.15 + 0.05 = 0.6

The intersection of A and B are:

P(A ∩ B) = E4

P(A ∩ B) = 0.25

The required probability for the intersection of A & B = 0.25