Problem $14-9$ Calculating WACC $[$LO$3]$

Ninecent Corporation has a target capital structure of $70$ percent common stock, $5$

percent preferred stock, and $25$ percent debt. Its cost of equity is $10$ percent, the cost of

preferred stock is $6$ percent, and the pretax cost of debt is $7$ percent. The relevant tax

rate is $22$ percent.

a$.$ What is the company's WACC? $($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? $($Do not round intermediate calculations and enter

your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$