A PAM source generates four symbols 3 V, 1 V, -1 V and -3 V with probability of p(3) = p(-3) = 0.2 and p(1) = p(-1) = 0.3 respectively. The variance for the source will be

A PAM source generates four symbols 3 V, 1 V, -1 V and -3 V with proba

1.	A PAM source generates four symbols 3 V, 1 V, -1 V and -3 V with probability of p(3) = p(-3) = 0.2 and p(1) = p(-1) = 0.3 respectively. The variance for the source will be
A.	4.2 V
B.	3.2 V
C.	3.6 V
D.	4.6 V
Answer» B. 3.2 V