In the table, where are the values of present worth and cumulative present worth coming from? How do I calculate them? No matter what I do, I cannot calculate these values. Please help.
Scenario I - Sales increases by 150 units per annum
Year Costs No Contribution Total Contribution of Units Sold Present Worth Cumulative PW
0 -1320 -1320 -1320
1 150 6.68 1002 954.29 -365.71
2 300 6.68 2004 1817.69 1451.97
3 450 6.68 3006 2596.70 4048.67
4 600 6.68 4008 3297.39 7346.06
5 750 6.68 5010 3925.47 11271.53
6 1006 6.68 6012 4486.25 15757.77
7 1050 6.68 7014 4984.72 20742.49
8 1200 6.68 8016 5425.54 26168.04
9 1350 6.68 9018 5813.08 31981.12
10 1500 6.68 10020 6151.41 38132.53
11 1650 6.68 11022 6444.34 44576.87
12 1800 6.68 12024 6695.41 51272.28
13 1950 6.68 13026 6907.97 58180.24
14 2100 6.68 14028 7085.09 65265.34
15 2250 6.68 15030 7229.69 72495.02