



 
Hi, The volume $V$ of a sphere of radius $r$ meters is given by \[V = \frac43 \pi \;r^3 \mbox{ cubic meters.}\] Your hemisphere has volume $700 \pi $ meters cubed so the whole sphere would have volume $1400 \pi $ cubic meters. thus \[1400\; \pi = \frac43 \pi \; r^{3} .\] Solve for $r.$ Penny  


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