<PRE><B>Question 285074</B>
1 cubic foot of water is about 7.48 gallons.
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The volume = Area of the circle * height of the column.  This is the formula for the volume of a cylinder, which is what you will have.
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Area = pi*r^2 = pi*7.5^2 = 176.71 square feet
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Assuming you want to fill the pool to the rim, that is 42 inches, which = 3.5 ft.
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3.5 ft * 176.71 ft^2 = 618.485 ft^3
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618.485 ft^3 * 7.48 gallons/ft^3 = 4626.27 gallons
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Done</PRE>