Respuesta :
since the equation for volume of a sphere is 4/3* π*r^3, you just plug in the radius. if you do this you get 4/3*421.875*π. multiply 4/3 and 421.875 and you get 562.5. now since it says EXACT, leave it in terms of pi; your answer would be 562.5π ft^3. if it said estimated or something along those lines then you would multiply by 3.14...... but since it says exact you leave pi alone.
V=(4/3)(pi)r^3
r=7.5
V=(4/3)(pi)(7.5^3)
V=(4/3)(pi)(7.5^3)
V=(4/3)(pi)(421.875)
V=562.5pi ft^2
if you watnt to you can aprox pi=3.14
V=562.5*3.14
V=1766.25 ft^3