The appropriate discount rate is 5.41%. Sales volumes are 85, 98, 106, 114 and 93 thousand units; monetary totals are in thousands, consistently with equipment cost 21,000 and annual fixed costs 900. Price per unit is 325 and variable cost 240. Comparable equity beta 1.2 at D/E 0.8 is unlevered as 1.2/[1+0.65×0.8], then relevered at target D/E 1. Risk-free and debt rates are 3%, market premium 4.5%. This gives equity beta 1.302632, equity cost 8.8618% and WACC 5.4059%.
CFdisposal=4200−0.35(4200−(21000−4200×5))=2,730.00 NPV=(−21,000)+1.054059212,818.75+1.0540592125,877+1.0540592136,481.50+1.0540592146,923.50+1.05405921512,458.25 NPV = 7,681.94. Accept.