A -6% grade and a +2% intersect at Sta 12 + 200 whose elevation is at 14.375 m. The two grades are to be connected by a parabolic curve, 160 m long. Find the elevation of the first quarter point on the curve.

The following table shows the stations and ordinates for a mass diagram. The free-haul distance is 600 ft. Overhaul cost is $12 per station yard. (a) Use the method of moments to compute the additional cost that must be paid to the contractor. (b) Sketch the ground profile if the finished grade of this roadway section is level (0 percent).