Please do part B

Estimate the average basin precipitation in mm for the rainfall and drainage basin shown in the figure. Each square is equivalent to $1k{m}^2$ and the total area is $117k{m}^2.$ Each station is identified with a letter that corresponds to the precipitation value shown in the table Show all computations and units.

A$)$ Compute the average precipitation using two different methods

a$)$ Arithmetic average station method

b$)$ Thiessen method

B$)$ Determine the total precipitation volume in $m^3$ based on the arithmetic average method results.