Fixed Income Question

Can somone explain to me how to answer this question? I am having troubl solving and I dont have the explanation to the solution. R.T. Farris purchased a 5-year, $100,000 parvalue, 8% annual coupon bond at a 8.4% yield to maturity. In order to realize a compound return of 7.9%, the amountFarris will have to earn in reinvestment income over the bond’s life is closest to: Thanks!

sorry wrong forum … this should be in CFA level 1

my god. i have no idea how to answer this

i would have to playu around with this but i think i can solve it…overconfidence bias.