Suppose you're designing a bridge for vehicle traffic over the Cache la Poudre River. The bridge will span 1350 feet. Two girder designs are under consideration for the bridge. The first design is expected to result in superstructure weight per foot 14(S) 1500; the second will result in a superstructure weight per foot of 17(S) 1250 where S is the span between piers. Piers and the two required abutments are estimated to cost $200, 000 each. The superstructure will be erected at a cost of $0.60 per lb