y ( feet ) - - - - - . 79 - - - . 70 - - . . . .. 63 .- -.. 30 DO -78 15 145 75 105 135 165 195 225 x ( feet ) 30 60 90 120 150 180 210 240 Suppose a plot of land runs 240 feet along a straight road, as represented in the given graph. Joe subdivides the plot into 8 subintervals, and uses surveyor equipment to measure the distance from the midpoint of each subinterval to the curved boundary of the plot of land. Joe's measurements are given (in red) in the diagram above. Each subinterval appears as a rectangle having a base of ... 45 feet 15 feet O 7.5 feet 30 feet