Suppose that MNINK Industries' capital structure features 64 percent equity, 8 percent preferred stock, and 28 percent debt. Assume the before-tax component costs of equity, preferred stock, and debt are 11.40 percent, 9.30 percent, and 8.00 percent, respectively.

What is MNINK's WACC if the firm faces an average tax rate of 21 percent and can make full use of the interest tax shield?