vineyard wines corp. issued $15-$year bonds, three years ago. the bonds have an annual $6\mathrm{.}75$ per cent coupoun rate and pay coupouns semi$-$annually. currenlty, the bonds are selling at $97\mathrm{.}8$ per cent of face value resulting on a yield$-$to$-$matuirty of $7\mathrm{.}024$ per cent. what is the after$-$tax cost of debt if the tax rate is $34$ per cent?