Year	Benefits	Costs	Discnt Fctr	PV for B	PV for C
1	0	647000	1.07	0	604672.9
2	105000	15000	1.1449	91711.07	13101.58
3	105000	10000	1.225043	85711.28	8162.979
4	105000	10000	1.310796	80104	7628.952
5	105000	10000	1.402552	74863.55	7129.862
6	105000	10000	1.50073	69965.93	6663.422
7	105000	10000	1.605781	65388.72	6227.497
8	105000	10000	1.718186	61110.96	5820.091
9	105000	10000	1.838459	57113.04	5439.337
10	105000	10000	1.967151	53376.68	5083.493

Sum of PV Benefits & Present Value Costs:

639345.2

669930.1

Benefit - Cost Ratio:

< compute here, at 7% discount rate; modify to 5% discount rate for sensitivity analysis