Problem $11-9$ WACC $($LG$11-2)$

Suppose that MNINK Industries' capital structure features $63$ percent equity, $7$ percent preferred stock, and $30$ percent debt Assume the before$-$tax component costs of equity, preferred stock, and debt are $11\mathrm{.}50$ percent, $9\mathrm{.}40$ 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.