Pfd Company has debt with a yield to maturity of 7.2%, a cost of equity of 13.4%, and a cost of preferred stock of 9.9%. The market values of its debt, preferred stock, and equity are $11.3 million, $3.1 million, and $13.5 million, respectively, and its tax rate is 40%. What is this firm's after-tax WACC? Pfd's WACC is %. (Round to two decimal places.)