Question

Use a finite sum to estimate the average value of f on the given interval by partition the interval into four subintervals of equal length evaluating f at the subinterval midpoints.

f(x)=x^3 on [2,4]

Answer 1

well the sum intervals have a width of 1/2 units

so find f(2), f(5/2), f(3), f(7/2) and f(4)


so rectangle 1 has a height (f(2) + f(5/2))/2 etc

hope it makes sense

Answer 2

8+125/8+27+343/8+64=315/2