The graph below shows a system of equations: (image below)
the x-coordinate of the solution to the system of equations is

The physical fitness of an athlete is often measured by how much oxygen the athlete takes in (which is recorded in milliliters per kilogram, ml/kg). the mean maximum oxygen uptake for elite athletes has been found to be 60 with a standard deviation of 7.2. assume that the distribution is approximately normal.

With: label the vertices and all the elements needed. find x

How to do this , and can some one explain