The midpoint Rule says that the Area can be found by summing up the areas of 'n' rectangles, each with length a/n and height of midpoint width.
a = 170
n = 5
midpoint widths are given as 2nd,4th,6th,8th, 10th intervals.
Area = 34(20.8 + 29+27.4+20.5+9.1)
Area = 3631.2