How do I find the PV of the following using an excel NPV formula:

PV of after-tax salaries:

PV of after-tax signing bonus

PV of MBA program costs:

NPV of undertaking the MBA program at each Wilton:

If the signing bonus: $20,000

Annual cost of MBA program: $78,000

Length of MBA program = 2 years

Initial base salary after program completion: $110,000

growth rate of salary= 4%

discount rate: 6.30%

tax rate 31%

And there is an expected 40 years until retirement and Ben is not able to work during the length of the program.

Current job info before beginning MBA program:

current salary (C): $65,000

growth rate of salary 3.0%

discount rate: 6.30%

tax rate 26%