explain/ show to get answer using excel

Allied Managed Care Company is evaluating two different computer systems for handling provider claims.

There are no incremental revenues attached to the projects, so the decision will be made on the basis of

the present value of costs. Allied's corporate cost of capital is 10 percent. Here are the net cash flow

estimates in thousands of dollars:

Year System X System Y

0 -$500 -$1,000

1 -$500 -$300

2 -$500 -$300

3 -$500 -$300

a. Assume initially that the systems both have average risk. Which one should be chosen?

b. Assume that System X is judged to have high risk. Allied accounts for differential risk by adjusting its

corporate cost of capital up or down by 2 percentage points. Which system should be chosen?