Answer
$ h = 1.69\times 10^6 \ m$
Work Step by Step
We simplify the equation for the period of a satellite for r to find:
$r =\sqrt[3] {\frac{GMT^2}{4\pi^2}}$
Plugging in the value of G, a constant, the mass of the earth, and 7200 seconds for the period (T), we find:
$r=8.06\times 10^6$
Subtracting the radius of the earth gives:
$ h = 1.69\times 10^6 \ m$