Cullumber Co0. has a capital structure, based on current market values, that consists of 40 percent debt, 19 percent preferred stock. and 41 percent common stock. If the returns required by investors are 9 pereent, 11 percent, and 15 percent for the debt, preferred stock, and common stock, respectively, what is Cullumber's after-tax WACC? Assume that the firm's marginal tax rate is 28 percent. (Do not round intermediate calculations. Round answer to 1 decimal place, es. 15.2\%) After tax WACC \%