document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=978613>Question 978613</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Given the geometric sequence: 20,(5/2),(5/16)  ...  \r<BR>\n" );
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document.write( "Find an explicit formula for a_n. <BR>\n" );
document.write( "a_n =        \r<BR>\n" );
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document.write( "Find a_(8) =  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #599977 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=599977\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the ratio is from 20 to 5/2 or from 40/2 to 5/2 and that is 1/8.\r<BR>\n" );
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document.write( "A(n)=A*r^n-1\r<BR>\n" );
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document.write( "n=8<BR>\n" );
document.write( "n-1=7<BR>\n" );
document.write( "A=20<BR>\n" );
document.write( "r=1/8<BR>\n" );
document.write( "EXPLICIT FORMULA IS A(n)=20*(1/8)^n-1\r<BR>\n" );
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document.write( "A(8)=20*(1/8)^7<BR>\n" );
document.write( "=9.536 X 10^-6, or 0.000009536\r<BR>\n" );
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document.write( "For a fraction,<BR>\n" );
document.write( "5 will be the numerator, and 16*(8^5), which are the number of terms left for the denominator,=<BR>\n" );
document.write( "524288<BR>\n" );
document.write( "5/(524288)=the above number.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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