document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=972438>Question 972438</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I have 20 surveys and my average is 84% how many 100% (perfect surveys) do i need to get my average above 91% </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #594762 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=594762\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> average = total/number.\r<BR>\n" );
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document.write( "Average is 0.84, number is 20, so total is 16.8\r<BR>\n" );
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document.write( "Let x = number of perfect surveys needed.\r<BR>\n" );
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document.write( "{16.8 +x}/(20+x)  = 0.91\r<BR>\n" );
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document.write( "multiply by (20+x) both sides\r<BR>\n" );
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document.write( "16.8 +x = 18.2 +0.91 x<BR>\n" );
document.write( "-1.4 =-0.09 x\r<BR>\n" );
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document.write( "need between 15 and 16 surveys, so round up to 16 surveys.\r<BR>\n" );
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document.write( "Check<BR>\n" );
document.write( "36 will be the number of surveys.<BR>\n" );
document.write( "The total will be 16.8+12=32.8\r<BR>\n" );
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document.write( "32.8/36=0.9111 (repeat)\r<BR>\n" );
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document.write( "Try 35 surveys (15 more)<BR>\n" );
document.write( "31.8/35 =0.9086.\r<BR>\n" );
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document.write( "You need 16 more surveys. </SPAN>\n" );
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