According to the following information, what is the firm's optimal capital structure? Proportion Earnings Per Weighted Average Cost of Debt Share (EPS) of Capital (WACC). - 30% $2.50 13.2% 40 3.80 12.7 50 4.75 12.4 60 5.25 12.8 50% To determine the optimal capital structure, the market value of the stock must be known 60% 30% 40%