20. A company mast make annual payments of 52000 at the ead of each year for 15 yean. It plans to buy two zero coupon bobds to fund these payments. The first bood matures in 4 years and the socond bond materes ia 9 yean, and both are purchused to yield 5% effective. The company wants to achieve the first two conditions of Redington immunization. How much should the company itivest in the 9-ytat bood