For bonds, assume coupons paid semi-annually, coupon rates and yields quoted with semi-annual compounding, and redeemable at par unless otherwise noted

- A company has a 7 year annuity paying $100 a year as a liability. The company can invest in zero-coupon bonds of any maturity. Yields are 5% for the annuity and all bonds. Construct a portfolio that would immunize the liability.