document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1191257>Question 1191257</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You want to obtain a sample to estimate a population proportion. You have no reasonable estimate for the population proportion p. You would like to construct a 99% confidence interval so that your interval estimate is within 2% of the true population proportion.\r<BR>\n" );
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document.write( "How large of a sample size is required? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #823136 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=823136\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> error=half-interval of a 99%CI=z(0.995)*sqrt(0.5*0.5/n) for most conservative estimate.<BR>\n" );
document.write( "0.02=2.576*sqrt(0.25/n)<BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( "0.0004=6.636*0.25/n<BR>\n" );
document.write( "n=1.6589/0.0004<BR>\n" );
document.write( "=4147.36 or 4148 units </SPAN>\n" );
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