Question

I've calculated the Expected Values of lotteries X1 and X2 to be E(X1)=25.125 and E(X2)=1. How do I now calculate the variance from these values? I know it's simple, but I'm a little confused.

Answer 1

i think you need \(\sum_xx^2P(x)-E(x)^2\) so it really depends on more than just the expected value

Answer 2

Ok, I think I've actually found the answer to my own question. It's using the Expected Value Criterion. It states that V(X)=E(X). I think I've got it. Thanks anyway.