A company has target weights of debt, preferred and common equity of 20%, 10% and 70%, respectively. It has liquidation values of debt, preferred and common equity of 30%, 15% and 55%. Its book values of debt, preferred and common equity are 40%, 10% and 50%. The estimated costs, net of adjustments, to the issuer are 4%, 8% and 11% for debt, preferred and common equity. Estimate the firm's weighted average cost of capital.