Finding the Density of a given object

[iJpawn]

The density of an object equals its mass divided by its volume. The mass of Earth is 6x10e+24 and its radius is 4000 miles (1.61km = 1mile). What is the density of the Earth in kg/m^3?V=4/3pi(r)^3. D=M/VConverting 4000 to Km, I get 6400. After plugging it into the Volume equation, I end up with approximately 1x10e+12. I divide 6x10e+24 by 1x10e+12, and my result is 6x10e^12. Is this the correct way to do the given problem? My answer sheet from my professor does not state this as any of the answers, and I can't think of any other way to approach this equation.

 

[iJpawn]

The answer should be in kg/m^3.

 

[haruspex]

The density of an object equals its mass divided by its volume. The mass of Earth is 6x10e+24 and its radius is 4000 miles (1.61km = 1mile). What is the density of the Earth in kg/m^3?V=4/3pi(r)^3. D=M/VConverting 4000 to Km, I get 6400. After plugging it into the Volume equation, I end up with approximately 1x10e+12. I divide 6x10e+24 by 1x10e+12, and my result is 6x10e^12. Is this the correct way to do the given problem? My answer sheet from my professor does not state this as any of the answers, and I can't think of any other way to approach this equation.

Your calculation is hard to follw if you do not state the units at every point. The answer is much too high.
I suspect you erred in converting cu km to cu m.
What units are the given mass in?

 

[iJpawn]

The mass of Earth is given in 6x10e+24kg, sorry for not posting it earlier!

 

[haruspex]

The mass of Earth is given in 6x10e+24kg, sorry for not posting it earlier!

Ok, but repost your calculation showing units at every step. Omit no steps.