Cost of debt. Dunder$-$Mifflin, Inc. $($DMI$)$ is selling $600,000$ bonds to raise money for the publication of new magazines in the coming year. The bond will pay a coupon rate of $9\mathrm{.}6\%$ with semiannual payments and will mature in $30$ years. Its par value is $$100.$ What is the cost of debt to DMI if the bonds raise the following amounts $($ignoring issuing costs$)?$

a$.$ $$57,564,000$

b$.$ $$51,936,000$

c$.$ $$73,854,000$

d$.$ $$79,644,000$

a$.$ What is the cost of debt to DMI if the bonds raise $$57,564,000?$

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

b$.$ What is the cost of debt to DMI if the bonds raise $$51,936,000?$

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

c$.$ What is the cost of debt to DMI if the bonds raise $$73,854,000?$

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

d$.$ What is the cost of debt to DMI if the bonds raise $$79,644,000?$