please explain

Bay Beach Industries wants to maintain their capital structure of 40% debt and 60% equity. The firm's tax rate is 34%. The firm can issue the following securities to finance the investments: Bonds: Mortgage bonds can be issued at a pre-tax cost of 6.2 percent. Debentures can be issued at a pre- tax cost of 6.2 percent Common Equity: Some retained earnings will be available for investment. In addition, new common stock can be issued at the market price of $50. Flotation costs will be $4 per share. The recent common stock dividend was $7.25. Dividends are expected to grow at 6% in the future. What is the cost of capital using mortgage bonds and internal equity? Set your calculator to 4 decimal places. PLEASE INPUT THE ANSWER IN PERCENT ROUNDING IT TO 2 DECIMALS. DO NOT INCLUDESIGN, EG INSTEAD OF 9.9922% INPUT 9.99