a cat scan produces equally spaced cross-sectional views of a human organ that provides information about the organ otherwise obtained only by surgery. suppose that a cat scan of a human liver shows cross-sections spaced 1.5 cm apart. the liver is 15 cm long and the cross-sectional areas, in square centimeters, are 0, 18, 58, 77, 94, 106, 118, 129, 63, 38, and 0. use the midpoint rule with n