The Tyler Oil Company's capital structure is as follows: The aftertax cost of debt is 10 percent; the cost of preferred stock is 13 percent; and the cost of common equity (in the form of retaine earnings) is 16 percent. a-1. Calculate Tyler Oil Company's weighted average cost of capital. (Round the final answers to 2 decimal places.) As an alternative to the capital structure shown above for Tyler Oil Company's, an outside consultant has suggested the following modifications. Under this new and more debt-oriented arrangement, the aftertax cost of debt is 11.5 percent, the cost of preferred stock is 14 percen and the cost of common equity (in the form of retained earnings) is 16.8 percent. b. Which plan is optimal in terms of minimizing the weighted average cost of capital? Plan 1 Plan 2