A firm’s current balance sheet is as follows: Assets $100 Debt $10 Equity $90 What is the firm’s weighted-average cost of capital at various combinations of debt and equity, given the following information? Debt/Assets After-Tax Cost of Debt Cost of Equity Cost of Capital 0% 8% 12% ? 10 8 12 ? 20 8 12 ? 30 8 13 ? 40 9 14 ? 50 10 15 ? 60 12 16 ? b) Construct a pro forma balance sheet that indicates the firm’s optimal capital structure. Compare this balance sheet with the firm’s current balance sheet.