I am having difficulty with this problem? Can someone EXPLAIN the steps on how you arrive at the answer so that I can understand this?

Here is the problem:

Estimate the area under the graph of the function f(2:} = .123 + 4 from a: = 1to a: = 2 using a Riemann sum with n = 10 subintervals and midpoints. Round your answer to four decimal places. area = NUmDE"