document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1148743>Question 1148743</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A simple random sample of 400 persons is taken to estimate the percentage of women in the Boston Teacher's Union whose total membership is 8000. Of those surveyed, 268 teachers are females. We can be 95 percent confident that between __ percent and ___ percent of the teachers in the union are females. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #770257 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=770257\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 268/400=72%<BR>\n" );
document.write( "95% interval has width 1.96*sqrt(.5*.5/400) or 0.049<BR>\n" );
document.write( "the exact interval is (0.671, 0.779)<BR>\n" );
document.write( "estimate by margin of error is 1/sqrt(n)=1/20=0.05, and get (0.67, 0.77) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );