Answer:
After tax cost of debt is 4.96%
Step-by-step explanation:
In order to compute the after-tax cost of debt, the yield to maturity to maturity which is pre-tax cost of debt needs to determined first of all using the rate formula in excel as provided below:
=rate(nper,pmt,-pv,fv)
nper is the time to maturity of the bond which is 20 years
pmt is the annual coupon receivable by investors $1000*5%=$50
pv is the current price of the bond less flotation cost per bond i.e($684.5-$50)=$634.5
fv is the future value of $1000 per bond
=rate(20,50,-634.5,1000)
rate=9.01%
after tax cost of debt=rate*(1-tax rate)
=9.01% *(1-0.45)
=4.96%