please answer in excel

4. First National Bank has a debt-to-equity ratio of 3. Its weighted average cost of capital is 12.50% and its cost of debt is 8%. First National Bank is subject to a 25% corporate tax rate. a. What is First National Bank cost of equity? b. What is First National Bank un-levered cost of capital? c. What would be its weighted average cost of capital is debt equity ratio is 0.5? 4