document.write( "Question 575073: Find the expense at 60 cents a square foot of polishing the curved surface of a marble column in the shape of the frustum of a right circular cone whose slant height is 12 feet and the radii of whose bases are 3 feet 6 inches and 2 feet 4 inches respectively. \n" ); document.write( "

Algebra.Com's Answer #369363 by Earlsdon(6294) $\"\"$ $\"About$

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The lateral surface area (S) of a frustum of a right circular cone is given by:
\n" ); document.write( " $\"S+=+pi%28r%5B1%5D%2Br%5B2%5D%29s\"$ where: $\"r%5B1%5D\"$ and $\"r%5B2%5D\"$ are the radii of the top and bottom respectively and s is the slant height.
\n" ); document.write( " $\"S+=+pi%282.4%2B3.6%2912\"$ Use $\"pi+=+3.14\"$ } approximation.
\n" ); document.write( " $\"S+=+3.14%286%29%2812%29\"$
\n" ); document.write( " $\"S+=+226.08\"$ sq.ft.
\n" ); document.write( "The cost of polishing, at $0.60 per square foot is:
\n" ); document.write( "226.08($0.60) = $135.65 \n" ); document.write( "

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