7. If two events, A and B are independent then the join probability P(A,B) is given by: a- P(A,B) = P(A) / P(B) P(A)p(B/A b- P(A,B) = PB) c- P(A,B) - P(A). P(B) 8. The variance o?) of a random signal represent: a- The total signal power. b- The AC signal power c- The DC signal power 9. The important properties of the probability density function p(x) was: a- P(x) dx = 0.5 b-LCP(x) dx = 0 00 SP(x) dx = 1 10- Referring to table beside, When Epxx (x,y) = 0.01, then: Table: Discrete joint probability 2- X=2.5 b-X-2 C-X=1 - X= 1.5 1 1.5 2 2.5 -1 0.15 0.03 0.06 0.05 -0.5 0.1 0.13 0.06 0.05 0 0.04 0.07 0.05 0.05 US 0.01 0.02 0.03 0.65