Williamson, Inc., has a debt-equity ratio of 2.60. The company's weighted average cost of capital is 9 percent, and its pretax cost of debt is 7 percent. The corporate tax rate is 25 percent.

c. What would the weighted average cost of capital be if the company's debt-equity ratio were .80 and 1.80? (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.)