The power W dissipated in a resistor is proportional to the square of the voltage V. That is,
$$W = rv^2$$
where r is a constant. If r = 3, and V can be assumed (to a very good approximation) to be a
normal random variable with mean $\mu = 6$ and standard deviation $\sigma = 1$, find
a. $E[W]$
b. $P(W > 120)$