Answer:
[tex]606.13cm^3[/tex]
Step-by-step explanation:
[tex]\frac{4}{3}\pi \left(\frac{21}{4}\right)^3[/tex]
[tex]\frac{4}{3}\pi\times \frac{21^3}{4^3}[/tex]
[tex]\frac{4\times \:21^3\pi }{3\times \:4^3}[/tex]
[tex]\frac{21^3\pi }{4^2\times \:3}[/tex]
[tex]\frac{7^3\times \:3^2\pi }{4^2}[/tex]
[tex]\frac{3087\pi }{4^2}[/tex]
[tex]\frac{3087\pi }{16}[/tex]
[tex]\approx 606.13103[/tex]