so, the cheetah's speed is 300/2.92 ft/sec
now, to convert it to miles/hr
well, there are 5280 ft in 1mile
and 60 minutes in 1hr
and 60 seconds in 1minute
so [tex]\bf \cfrac{300\ f}{2.92\ s}\cdot \cfrac{1\ mi}{5280\ f}\cdot \cfrac{60\ min}{1\ hr}\cdot \cfrac{60\ sec}{1\ min}\\\\\\ \cfrac{300\cdot 1\cdot 60\cdot 60}{2.92\cdot 5280\cdot 1\cdot 1}\cdot \cfrac{f}{f}\cdot \cfrac{min}{min}\cdot \cfrac{sec}{sec}\cdot \cfrac{mi}{hr}[/tex]
simplify away