Capital Co. has a capital structure, based on current market values, that consists of 30 percent debt, 3 percent preferred stock, and 67 percent common stock. If the returns required by investors are 10 percent, 11 percent, and 15 percent for the debt, preferred stock, and common stock, respectively, what is Capital's after tax WACC? Assume that the firm's marginal tax rate is 40 percent. (Round intermediate calculations to 4 decimal places, and final answer to 2 decimal places.)