document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=402584>Question 402584</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A random sample of medical files is used to estimate the proportion p of all people who have blood type B.  If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 85% sure that the point estimate  will be within a distance of 0.1 from p </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #284745 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=284745\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A random sample of medical files is used to estimate the proportion p of all people who have blood type B. If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 85% sure that the point estimate will be within a distance of 0.1 from p<BR>\n" );
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document.write( "Since ME = z*sqrt(pq/n)<BR>\n" );
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document.write( "n = [z/E]^2*pq<BR>\n" );
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document.write( "Your Problem:<BR>\n" );
document.write( "n = [1.440/0.1]^2*(1/2)(1/2)<BR>\n" );
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document.write( "n = 207.35*(1/4)<BR>\n" );
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document.write( "n = 52 when rounded up<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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