Interest tax shield benefit: Structural Corp. currently has a cost of equity capital equal to 15 percent. Assume that the Modigliani and Miller Proposition 1 assumptions hold, with the exception of the assumption that there are no taxes, and that the firm’s capital structure consists of 50 percent debt and 50 percent equity. What is the weighted average cost of capital for the firm if the cost of debt is 10 percent and the firm is subject to a 28 percent marginal tax rate?