Olsen Outfitters Inc. believes that its optimal capital structure consists of $40\%$ common equity and $60\%$ debt, and its tax rate is $25\%.$ Olsen must raise additional capital to fund its upcoming expansion. The firm will have $$1$ million of retained earnings with a cost of rs $=11\%.$ New common stock in an amount up to $$9$ million would have a cost of re $=12\mathrm{.}0\%.$ Furthermore, Olsen can raise up to $$3$ million of debt at an interest rate of rd $=9\%$ and an additional $$5$ million of debt at rd $=11\%.$ The CFO estimates that a proposed expansion would require an investment of $$4\mathrm{.}4$ million. What is the WACC for the last dollar raised to complete the expansion? Round your answer to two decimal places.