The duration of a corporate bond with a 8% coupon rate with annual coupon payments, 5 years of maturity, currently selling at par, is 4.312 years.

a. What will be the estimated bond price volatility using duration based estimation formula, if interest t rates decrease 0.75%

b. What will the bond price volatility using bond price volatility equation, if interest rates decrease 0.75%? compare the result with the estimated percentage change in the bond price in part a?