Pfd Company has debt with a yield to maturity of 6.6%, a cost of equity of 13.4%, and a cost of preferred stock of 9.4%. The market values of its debt, preferred stock, and equity are $15.4 million, $3.1 million, and $16.3 million, respectively, and its tax rate is 38%.

What is this firm's after-tax WACC?

Note: Assume that the firm will always be able to utilize its full interest tax shield.