Newton's analysis of the acceleration of a falling body with a law of universal gravitation could be called "weighing the Earth."

Assuming you could make a measurement in the laboratory of G by observing directly the attraction of two known masses, use the value of g that you found in this experiment to calculate the mass of the Earth given its radius $6\mathrm{.}37$ x $106$ meters. Assume G to be $6\mathrm{.}67$x$10-11$ SI units $($mass in kg$,$ distance in m$,$ time in s$).$ Explain your work well enough for us to evaluate it and identify errors if any.