document.write( "Question 1072565: find the 8th terms of the following series;
\n" ); document.write( "6.500 , 9.750 , 14.625
\n" ); document.write( "calculate rounding to the third decimal place, and show your workings \n" ); document.write( "

Algebra.Com's Answer #687461 by KMST(5328) $\"\"$ $\"About$

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$\"9.750=6.500%2A1.5\"$ and $\"14.625=9.750%2A1.5\"$
\n" ); document.write( "so this is a geometric sequence
\n" ); document.write( "with first term $\"b%5B1%5D=6.500\"$
\n" ); document.write( "and common ratio $\"r=1.5\"$ .
\n" ); document.write( "For a geometric sequence term number $\"n\"$ is
\n" ); document.write( " $\"b%5Bn%5D=b%5B1%5D%2Ar%5E%28n-1%29\"$
\n" ); document.write( "and the sum of the first $\"n\"$ terms is
\n" ); document.write( " $\"S%5Bn%5D=n%28r%5En-1%29%2F%28r-1%29\"$
\n" ); document.write( "In this case,
\n" ); document.write( " $\"b%5B8%5D=6.500%2A1.5%5E%288-1%29=6.500%2A1.5%5E7=6.5%2A17.0859375=111.05859375\"$
\n" ); document.write( "and
\n" ); document.write( " $\"S%5B8%5D=6.500%281.5%5E8-1%29%2F%281.5-1%29=6.500%2A25.62890625%2F0.5=333.17578125\"$ .
\n" ); document.write( "Rounding to the third decimal place,
\n" ); document.write( " $\"b%5B8%5D=111.059\"$ and $\"S%5B8%5D=333.176\"$ . \n" ); document.write( "

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