Answer:
1206.4 ft³
Explanation:
The formula for the volume of a cone is ...
V = (1/3)πr²h
Here, the radius is 8 ft and the height is 6 ft, so the volume of the conical top of this solid is ...
V = (1/3)·π·(8 ft)²·(6 ft) = 128π ft³
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The formula for the volume of a cylinder is ...
V = πr²h
Here, the radius is 8 ft and the height is 4 ft, so the volume of the cylindrical bottom of this solid is ...
V = π·(8 ft)²·(4 ft) = 256π ft³
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Then the total volume of the solid is the sum of these, or ...
total volume = volume of cone + volume of cylinder
= 128π ft³ + 256π ft³ = 384π ft³
total volume ≈ 1206.4 ft³
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We used a value of pi with sufficient accuracy to give us 6 good significant digits in the answer. That is necessary if we're to round to 5 significant digits. (3.14 doesn't work for this; it gives you 1205.8 ft³.)