Pfd Company has debt with a yield to maturity of 6.6%, a cost of equity of 13.6%, and a cost of preferred stock of 10.2%. The market values of its debt, preferred stock, and equity are $9.9 million, $3.4 million, and $13.8 million, respectively, and its tax rate is 22%. 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.) )