The Beta Corporation has an optimal debt ratio of 40 percent. Its cost of equity capital is 12 percent and its before-tax borrowing rate is 8 percent. Given a marginal tax rate of 30 percent. a. Calculate the weighted-average cost of capital. (Do not round intermediate calculations. Round your answer as a percent rounded to 2 decimal places.) Weighted-average cost of capital 4 b. Calculate the cost of equity for an equivalent all-equity financed firm. (Do not round intermediate calculations. Round your answer as a percent rounded to 2 decimal places.) Cost of equity