I am now confused so please figure this questions out for me

A $1 000 face value bond has a coupon of 4% ( paid annually ) and will mature 17 years from today ? A . Assume that the yield - to - maturity is 4 5% . What is the bond's : 1 . Duration 1 . Modified Duration B . Assume that the bond's yield - to - maturity immediately changes from 4 .5 % to 3 5 % ( the bond still has 17 years to maturity ) i . Estimate the / change in the bond's price using modified duration i . What is actual bond price ( at Y IM - 3 5% ) , and the / price change ( from YIM - 4.5 % to 3.5 % ) ? 1 1 . Why is there a ( large ) difference between the actual and estimated / price changes in this case