A. (100 - 25pie sign) sq in. b. 75 pie sign sq in. c. (100 - 12.5pie sign) sq in. d. 87.5 pie sign sq in.

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6