3. You are interested in buying a new machine that will increase the firm's revenues and decrease its costs. The machine costs $250,000 today (time zero). It will provide positive cash flows of $100,000 in year 1, $120,000 in year 2 and $150,000 in year 3 and then a negative cash flow of $60,000 in year 4. The firm's required rate of return (WACC or k) is 9%. Calculate the NPV, IRR and payback period of the investment. Should we invest