Pfd Company has debt with a yield to maturity of 5.9%, a cost of equity of 13.2%, and a cost of preferred stock of 8.7%. The market values of its debt, preferred stock, and equity are $11.7 million, $3.4 million, and $15.2 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.)