Pfd Company has debt with a yield to maturity of 8.2%, a cost of equity of 15.1%, and a cost of preferred stock of 9.3%. The market values of its debt, preferred stock, and equity are $14.6 million, $2.7 million, and $14.2 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.