Answer:
Net Present Value (NPV) is 506
Explanation:
See document attached. Â To get the net present value, Â we make a cash flow in excel. Â
At moment 0 we have the investment cost , in this case $13,400. From period 1 to period 4, we have different incomes. Then, we calculate the Net cash flow that is the difference between benefits and cost.
To get  net present value,  we use VNA formula. Â
=VNA(required rate of return; Net cash flow from moment 1 to moment 4 )+Net cash flow at moment 0