A comment is made in the paragraph that follows Equation 7.14 suggesting the selection of the radius of influence (r0) is somewhat arbitrary (i.e., the discharge is not overly sensitive to this variable). Suppose the radius of influence for a 20-cm-diameter well is approximately 400 m (plus or minus 50 meters). Determine the percent error in discharge that results from this 12.5-percent range in radius of influence. Assume the 50-m-thick, unconfined aquifer (course sand) and the drawdown at the well is l 0 m.