Suppose that B$2$B$,$ Inc. has a capital structure of $37$ percent equity, $18$ percent preferred stock, and $45$ percent debt. Assume the

before$-$tax component costs of equity, preferred stock, and debt are $15\mathrm{.}5$ percent, $13\mathrm{.}0$ percent, and $10\mathrm{.}5$ percent, respectively.

What is B$2$B$\text{'}$s WACC if the firm faces an average tax rate of $21$ percent and can make full use of the Interest tax shield? $($Round your

answer to $2$ decimal places.$)$

Answer is complete but not entirely correct.