Micro Spinoffs Inc. issued 10-year debt a year ago at par value with a coupon rate of 8%, paid annually. Today, the debt is selling at $1,280. If the firm’s tax bracket is 40%, what is its percentage after-tax cost of debt? Assume a face value of $1,000. (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) After-tax cost of debt %