CAPM BASED:

$4\mathrm{.}9.$ Epperly Fund invests in S&P$500$ companies and thereby simulates a market portfolio. The expected return of Epperly is $13\mathrm{.}5\%,$ with a standard deviation of $10\%.$ Suppose you are able to borrow $$10,000$ at the riskless rate of $9\%,$ and you already have $$10,000$ of your own money. If you invest this $$20,000$ in Epperly Fund, what is the probability that you will have a return greater than $25\%$ on your own money?