Answer:
4.51%
Step-by-step explanation:
First, find the yield to maturity(YTM) of the bond; this would be the pretax cost of debt.
Using a financial calculator, input the following;
Face value of the bond ; FV = 1000
Semiannual coupon payment; PMT = (8%/2)*1000 = 40
Present value of bond; PV = -1050
Time to maturity; N = 20*2 = 40 semiannual payments
then compute semi-annual interest rate ; CPT I/Y = 3.756%
The pretax cost of debt = 3.756% *2 = 7.51%
After tax-cost of debt is used for WACC calculation and is therefore as follows;
7.51%(1-0.40) = 4.51%