document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1059759>Question 1059759</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A doctor wants to estimate the HDL cholesterol of all&#8203; 20- to&#8203; 29-year-old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming &#963;=10.2? Suppose the doctor would be content with 95 % confidence. How does the decrease in confidence affect the sample size&#8203; required? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #674856 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=674856\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The interval width is z*sigma/sqrt (n)=2; z(.995)=2.576. <BR>\n" );
document.write( "Square everything <BR>\n" );
document.write( "4=2.576^2*10.2^/n<BR>\n" );
document.write( "N=690.386/4<BR>\n" );
document.write( "=172.59 or 173<BR>\n" );
document.write( "With 95%, z=1.96 and its square is 3.8416<BR>\n" );
document.write( "The smaller value will lessen the numerator and decrease the sample size (to 100). <BR>\n" );
document.write( "Less confidence with no other changes will cause a smaller sample size.  </SPAN>\n" );
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