Pfd Company has debt with a yield to maturity of 7.8%, a cost of equity of 14.4%, and a cost of preferred stock of 8.8%. The market values of its debt, preferred stock, and equity are $15.5 million, $2.6 million, and $14.4 million, respectively, and its tax rate is 21%. What is this firm's after-tax WACC? Note: Assume that the firm will always be able to utilize its full interest tax shield. Pfd's WACC is %. (Round to two decimal places.)