Answer:
11.3 ft
Step-by-step explanation:
[tex]V_{gravel}=3,200\: ft^3\\\\height \:(h) =24\: ft\\\\ To \: find:\: radius\:(r)[/tex]
Since, gravel is in the shape of right circular cone.
[tex]\implies V_{gravel}= \frac{1}{3}\pi r^2 h\\\\\implies 3,200= \frac{1}{3}(3.14) r^2 (24)\\\\\implies r^2=\frac{3,200\times 3}{3.14\times 24}\\\\\implies r^2=\frac{9,600}{75.36}\\\\\implies r^2=127.388535\\\\\implies r=\pm\sqrt{127.388535}\\\\\implies r=\pm 11.286653\\radius\: can't\: be\: negative\\\\\implies r=11.286653\\\\\implies r \approx 11.3 \: ft[/tex]