Find the elapsed time between 8: 29 a. m. and 11: 14 a. m. 3 hours, 15 minutes 2 hours, 45 minutes 9 hours, 15 minutes 14 hours, 45 minutes

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