Darwin Dairy is thinking about buying a new bottling machine. The machine requires an initial investment of $75,000 and will have no salvage value at the end of its useful life. Darwin expects the machine to produce net annual cash flows of $15,500. In addition, it expects the machine to save $1,200 per year in lost product costs. If the project's estimated NPV is $17,431 and Darwin is using a 9% discount rate, what is the estimated life of the machine? Years PV of an Annuity for 9% 6 4.4859 7 5.033 8 5.5348 9 5.9952 9 years 7 years 6 years O 8 years