Advanced Robotics is evaluating two projects with the following net cash flows. The company's required rate of return on investments is 7%. (PV of $1, FV of $1, PVA of $1, and FVA of $1).

Year	Project RoboAlpha	Project RoboBeta
0	$(600,000)	$(550,000)
1	$160,000	$150,000
2	$200,000	$180,000
3	$240,000	$210,000
4	$280,000	$240,000

a. Calculate the payback period for each project. Which project is preferred based on the payback period?

b. Calculate the net present value for each project. Which project is preferred based on the net present value?