Ying Import has several bond issues outstanding, each making semiannual interest payments. The bonds are listed in the table below. If the corporate tax rate is $24$ percent, what is the aftertax cost of the company$$s debt?

$\backslash$table$[[$Bond$,$Coupon Rate,Price Quote$],[1,8\mathrm{.}90\%,106\mathrm{.}4],[2,6\mathrm{.}90,94\mathrm{.}0],[3,8\mathrm{.}60,105\mathrm{.}2],[4,9\mathrm{.}10,95\mathrm{.}0]]$