Ryan is building a treehouse. It will take 71 ¼ hours to complete. He can work on the tree house 16½ hours each week. To the nearest tenth, how many weeks will it take Ryan to complete the tree house?

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