Question

If X is a random variable and E(X) =1.5, then what is the value of E(3 + 4X)?

Answer 1

E(3 + 4X)

= E(4x + 3)

= 4.E(x) + 3

= 4.(1.5) + 3

= 6 +3 = 9

since E(ax+b)

= aE(x)+b.