Expectation of a product(statistics)?

Question

How do you calculate E(AB)?
I'm trying to compute the expected value of a product. Specifically, I need to know how to find E(Xbar^2) with the bernoulli distribution in mind where Xbar = sum(xi)/n

Thanks

Answer 1

E(Xbar^2) = E(Xbar) * E(Xbar)

E(Xbar) = E(X)

Therefore E(Xbar^2) = E(X) ^ 2

Answer 2

if A and B are independent then
E(AB)=E(a)E(B)

for ur case the trials r independent, so u can use this one...