Let x = length of chain (ft).
Because the linear density of the chain is 0.87 lb/ft, the weight of the chain is
W = (0.87 lb/ft)*(x ft) = 0.87x lb.
The weight should be kept below 1.9 lb, therefore
0.87x < 1.9
x < 1.9/0.87
x < 2.184 ft
A length of 2.18 ft will satisfy this condition.
Answer: 2.18 ft (nearest thousandth)
