document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1190492>Question 1190492</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In order to compute the area of a particular circle, Juan first measures the length of its diameter. The actual diameter is 20 cm, but Juan's measurement has an error of up to 20%. What is the largest possible percent error, in percent, in Juan's computed area of the circle?\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #822163 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=822163\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> if the error is + 20%, then he measures the diameter as 24.<BR>\n" );
document.write( "if the error is - 20%, then he measures the diameter as 16.<BR>\n" );
document.write( "if he is 0%, then he measures the diameter as 20.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the radius is half the diameters, so the radius can be 8, or 10, or 12.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the area of the circle is equal to pi * r^2.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the area can therefore be 64 * pi, or 100 * pi, or 144 * pi.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the correct area is 100 * pi.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if the area measures 64 * pi, then the error is 100 * pi - 64 * pi = 38 * pi.<BR>\n" );
document.write( "38 * pi / (100 * pi) is an error of 38%.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if the area measures 144 * pi, then the error is 144 * pi - 100 * pi = 44 * pi.<BR>\n" );
document.write( "44 * pi / (100 * pi) is an error of 44%.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "it looks like the largest possible error in determining the area of the circle will be 44%.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "let me know if you have any questions.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "theo\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );