for this problem... for problem question b.... why do we have to multiply 10^3?

1. A steel wire 300 feet long and inch in diameter weighs 0.042 #/ ft. If the wire is suspended vertically from its upper end, calculate (a) the maximum tensile stress due to its own weight and (b) the maximum weight W that can be safely supported assuming a safety factor of three and an ultimate tensile stress of 65 ksi