You have been managing a $$5$ million portfolio that has a beta of $1\mathrm{.}70$ and a required rate of return of $15\%.$ the current risk free rate is $5\mathrm{.}25\%.$ Assume that you recoeve another $$500,000.$ If you invest the money in a stock with a beta of $1\mathrm{.}60,$ what will be the required return on your $$5\mathrm{.}5$ million protfolio?