more interest payment to be made on the Series B bonds. b. Why does the longer-term (12-year) bond fluctuate more when interest rates change than does the shorter-term (1-year) bond? 7-8. (Bond valuation) ExxonMobil 20-year bonds pay 6 percent interest annually on a $1,000 par value. If the bonds sell at $945, what is the bonds' expected rate of return