document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1044002>Question 1044002</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a survey of 8000 &#8203;women, 5431 say they change their nail polish once a week. Construct a 90% confidence interval for the population proportion of women who change their nail polish once a week.\r<BR>\n" );
document.write( "\n" );
document.write( "A 90&#8203;% confidence interval for the population proportion is? Round to three decimal places as&#8203; needed </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #659254 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=659254\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> One sample proportion<BR>\n" );
document.write( "90% CI is z* SE<BR>\n" );
document.write( "z=1.282<BR>\n" );
document.write( "SE=sqrt{p*(1-p))/n)<BR>\n" );
document.write( "p=0.6789<BR>\n" );
document.write( "1-p=0.3211<BR>\n" );
document.write( "n=8000<BR>\n" );
document.write( "SE=0.0052<BR>\n" );
document.write( "CI on one side=1.282*0.0052=0.0067<BR>\n" );
document.write( "90% CI=(0.672,0.686), rounding at the end. This means that we are 90% confident that the true value lies in this interval.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );