Can anyone help with this question? I got 10.63% but it says that's wrong.

Olsen Outfitters Inc. believes that its optimal capital structure consists of 50% common equity and 50% debt, and its tax rate is 25%. Olsen must raise additional capital to fund its upcoming expansion. The firm will have $2 million of retained earnings with a cost of r_s = 13%. New common stock in an amount up to $6 million would have a cost of r_e= 14.5%. Furthermore, Olsen can raise up to $4 million of debt at an interest rate of r_d = 11% and an additional $6 million of debt at r_d = 14%. The CFO estimates that a proposed expansion would require an investment of $4.4 million. What is the WACC for the last dollar raised to complete the expansion? Round your answer to two decimal