XYZ Co. is considering a major expansion of its product line and has estimated the following cash flows associated with such an expansion. The initial investment would be $3,500,000 and the project would generate incremental cash flows of $800,000 per year for six years. The cost of capital is 10 percent. Please calculate the following:

1. Pay back period (PBP)
2. Calculate the Net present value (NPV)
3. Calculate the Profitability index (PI)
4. Calculate the Internal rate of return (IRR)
5. Should this project be accepted?
6. If cost of capital change to 12%,what will be the payback period and IRR?