$2.$ A new series of bonds to finance equipment is to be issued by Delay, Linger, and Wait Airlines. Each bond will have a face value of $$10,000$ and will bear a coupon rate of $8\%$ per year paid quarterly, and the bond series matures in $15$ years. The bid price by the successful underwriter is $$9,000$ per bond, less marketing expenses of $$5$ per bond. If the airline$$s effective income tax is $21\%,$ what is the effective after$-$tax cost of this new borrowed capital? Assume the redeem price is the same as the face value.