27. The Hazen Williams equation can be used to calculate the pressure drop, Pd (psi/ft of pipe) in pipes due to friction: P=4.520 / (Cd) where is the flow rate (gpm), C is a design coefficient determined by the type of pipe, and d is pipe diameter in inches. Consider a 3.5-in.-diameter steel pipe with C = 120. Calculate the pressure drop in a 1000-ft-long pipe for flow rates of 250, 300, 350, 400, and 450 gpm. To carry out the calcula- tion, first create a five-element vector with the values of the flow rates (250, 300,...). Then use the vector in the formula using element-by-element oper- ations.