4. A company has an optimal capital structure of 35% debt financing, 15% preferred stock financing, 50% common equity financing. The tax rate is 25%, the preferred stock dividend is $2 per share, next period's common stock dividend is $1 per share and is expected to grow by 5% in future years, the price of the company's common stock is $10, the price of the company's preferred stock is $25, the bond coupon rate is 4%. Assume that retained earnings is the only source of common equity financing. [15 points] a. Calculate the weighted average cost of capital. b. Suppose the operating profitability ratio is 5% and the capital requirement ratio is 55%. Calculate the return on invested capital. c. Is the Economic Value Added positive, negative, or zero for this company? d. Referring to your answers to parts a, b and c, do you anticipate that the stock price of this company will increase or decrease