document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1166657>Question 1166657</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A political candidate has asked you to conduct a poll to determine what percentage of people support her.\r<BR>\n" );
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document.write( "If the candidate only wants a 3% margin of error at a 99% confidence level, what size of sample is needed?\r<BR>\n" );
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document.write( "Give your answer in whole people.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #791182 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=791182\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> half-interval is z(0.995)*sqrt(p*(1-p)/n) use p=0.5 as the most conservative estimate. z=2.576<BR>\n" );
document.write( "half-interval is 2.576 * sqrt (.25)/n and that equals 0.03<BR>\n" );
document.write( "square both sides and 0.0009=6.634*.25/n<BR>\n" );
document.write( "so 0.0009n=1.6585<BR>\n" );
document.write( "n=1842.77 or 1843<BR>\n" );
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