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 $11\mathrm{.}40$ percent, $9\mathrm{.}30$ percent, and $8\mathrm{.}00$ 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?

Note: Round your answer to $2$ decimal places.