Need help with a simple problem: (4/3) (pi) (r^3)

[Eyeron notsmart]

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So I don't know how to do this problem, and it's the only one I'm having trouble with. My book never prepared me for what to do in this situation. I believe I'm supposed to multiply whatever the fraction, and decimal become by the r^3. But I don't know what to do with the fraction and decimal. So can somebody please explain what I'm supposed to do since my book didnt.

Any help is much apreciated

 

[JeffM]

[/IMG]

So I don't know how to do this problem, and it's the only one I'm having trouble with. My book never prepared me for what to do in this situation. I believe I'm supposed to multiply whatever the fraction, and decimal become by the r^3. But I don't know what to do with the fraction and decimal. So can somebody please explain what I'm supposed to do since my book didnt.

Any help is much apreciated

If you were asked to multiply 15 and (4/3) you would go

\(\displaystyle 15 * \dfrac{4}{3} = \dfrac{15}{1} * \dfrac{4}{3} = \dfrac{60}{3} = 20.\)

If you were asked to multiply 8 and (4/3) you would go

\(\displaystyle 8 * \dfrac{4}{3} = \dfrac{8}{1} * \dfrac{4}{3} = \dfrac{32}{3} \approx 10.67.\)

That same general approach works here:

\(\displaystyle \dfrac{4}{3} * 3.14 = \dfrac{4}{3} * \dfrac{3.14}{1} = \dfrac{12.56}{3} \approx 4.18.\)