Duchess Corporation now wishes to calculate its cost of common stock equity, r$\_$s$,$ by using the CAPM. The firm's investment advisors and its own analysts indicate that the risk$-$free rate, RF$,$ equals $3\mathrm{.}5\%$; the firm's beta, b$,$ equals $0\mathrm{.}7$; and the market return, rm$,$ equals $10\mathrm{.}0\%.$ What is the firms cost of common equity according to the CAPM?