For the cash flow shown below determine the value of X that
For the cash flow shown below, determine the value of X that will make the Net Present Worth at year 0 equal to $2,000 at an interest rate of 10% per year.
| Year | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 
| Cash flow($) | 100 | 100 | X | 200 | 300 | 400 | 500 | 1000 | 700 | 500 | 
Solution
Find X so that
NPW = NPW
2000 = 100(1+10%)^-0 + 100(1+10%)^-1 + X(1+10%)^-2 + 200(1+10%)^-3 + 300(1+10%)^-4 + 400(1+10%)^-5 + 500(1+10%)^-6 + 1000(1+10%)^-7 + 700(1+10%)^-8 + 500(1+10%)^-9
2000 = 2128.44 + X(1+10%)^-2
This gives X = (2000 - 2128.44)/(1+10%)^-2
= -155.41

