PLEASE FAST

dell Inc. is a publicly traded tech. goods company. The company has $ 520 million in book value of debt, reported interest expenses of $ 15.2 million in the most recent year and has an average maturity of 5 years for the debt. The pre-tax cost of debt for the firm is currently 4%. What is your best estimate of the market value of debt outstanding at the firm? (You can assume annual interest payments and a marginal tax rate of 40%)