document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=560157>Question 560157</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A medical researcher wishes to determine the percentage of females who take vitamins.  He wishes to be 99% confident that the estimate is within 2% of the true proportion.  How large should the sample size be? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #363743 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=363743\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A medical researcher wishes to determine the percentage of females who take vitamins. He wishes to be 99% confident that the estimate is within 2% of the true proportion. How large should the sample size be?<BR>\n" );
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document.write( "n = [z/E]^2*pq<BR>\n" );
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document.write( "Since \"p\" is not know you should use p = 1/2<BR>\n" );
document.write( "n = [2.3263/0.02]^2*(1/2)(1/2)<BR>\n" );
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document.write( "n = 3383 when rounded up<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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