$6$ p Problem $14-9$ Calculating WACC $[$LO$3]$ Nuttenhall Corporation has a target capital structure of $65$ percent common stock, $10$ percent preferred stock, and $25$ percent debt. Its cost of equity is $13$ percent, the cost of preferred stock is $8$ percent, and the pretax cost of debt is $9$ percent. The relevant tax rate is $25$ percent. a$.$ What is the company's WACC? Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$ b$.$ What is the aftertax cost of debt? Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$ Answer is complete but not entirely correct.