HELPPP with 3 A AND B

Plz me plz i will give a brain just plz

Julia is going for a walk through the neighborhood. what unit of measure is most appropriate to describe the distance she walks?

List x1, x2, x3, x4 where xi is the midpoint endpoint of the five equal intervals used to estimate the area under the curve of f(x) between x = 0 and x = 10.