S6.8 - Cumulative cash flows Self-tightening wedge grips are designed for tensile testing applications up to 1200 pounds.The cash flow associated with the product is shown below. Determine the cumulative cash flow after year 4. Year 2 3 4 Revenue, $ 15,000 25,000 29,000 13,000 Costs, $ -14,000 -28,000 -4,000 -16,000 The cumulative cash flow after year 4 is $