13. A $70000, 8.5% bond with semi-annual coupons redeemable at par in 12 years is purchased at 102.5. What is the approximate yield rate? 14. Can you describe the relationship between bond prices and interest rates? 15. A $9000, 11.5% bond with semi-annual interest coupons redeemable at par in 17 years is bought to yield 7.5% compounded semi-annually. Determine: (i) the premium or discount (ii) the purchase price