(Weighted average cost of capital) The target capital structure for QM Industries is 38 percent common stock, 6 percent preferred stock, and 56 percent debt. If the cost of common equity for the firm is 17.5 percent, the cost of preferred stock is 9.3 percent, the before-tax cost of debt is 7.8 percent, and the firm's tax rate is 35 percent, what is QM's weighted average cost of capital?