Answer:
A) Sewing machine:
initial outlay = -$305,500
net cash flow per year = (234 baseballs per hour - 130 baseballs per hour) x 1,400 hours x $0.48 per baseball = $69,888
NPV = -$305,500 + ($69,888 x 4.968) = -$305,500 + $347,203.58 = $41,703.58
Packing machine:
initial outlay = -$131,800
net cash flow per year = 1,200 hours x $26 per hour = $31,200
NPV = -$131,800 + ($31,200 x 4.968) = -$131,800 + $155,001.60 = $23,201.60
B) PVI of sewing machine = $347,203.58 / $305,500 = 1.137
PVI of packing machine = $155,001.60 / $131,800 = 1.176
C) They should invest in the packing machine since its PVI is higher, meaning that it increases the company's value by a higher amount per dollar invested.