In: Finance
A 10-year loan of 120,000 is to be repaid with payments at the end of each month. Interest is at an annual effective rate of 6.00%.
The first monthly payment is 800. Each additional payment will be k more than the previous month payment. Find k.
rate compounded monthly=((1+6%)^(1/12)-1)*12=5.8411%
The given annuity can be broken into two streams
Stream 1: Constant annuity of 800
Present
Value=800/(5.8411%/12)*(1-1/(1+5.8411%/12)^(12*10))=72579.32783
Stream 2: Arithmetic gradient annuity of k
Present
Value=k/(5.8411%/12*(1+5.8411%/12)^(12*10))*(((1+5.8411%/12)^(12*10)-1)/(5.8411%/12)-12*10)=4872.44843*k
Total Value=72579.32783+4872.44843*k
=>72579.32783+4872.44843*k=120000
=>k=(120000-72579.32783)/4872.44843
=>k=9.732411302