7. (20 pts.) Complete using excel and showing formula. Day and Night Hotels Corporation has a target capital structure of 70 percent common stock, 10 percent preferred stock, and 20 percent debt. Its cost of equity is 13 percent, the cost of preferred stock is 4 percent, and the pretax cost of debt is 6 percent. The relevant tax rate is 35 percent. What is Day and Nights' WACC? What is the after-tax cost of debt? a. b