a$.$ The after$-$tax cost of debt using the bond's yield to maturity $($YTM$)$ is $.($Round to two decimal places.$)$

The after$-$tax cost of debt using the approximation formula is $.($Round to two decimal places.$)$

b$.$ The cost of preferred stock is

$\%.($Round to two decimal places.$)$

c$.$ The cost of retained earnings is

$\%.($Round to two decimal places.$)$

The cost of new common stock is

$\%.($Round to two decimal places.$)$

d$.$ Using the cost of retained earnings, the firm's WACC is

$\%.($Round to two decimal places.$)$

Using the cost of new common stock, the firm's WACC is

$\%.($Round to two decimal places.$)$