document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1182977>Question 1182977</A>: <I><SPAN STYLE=\"word-break: break-all;\"> We wish to estimate what percent of adult residents in a certain county are parents.<BR>\n" );
document.write( "Out of 100 adult resident sampled, 35 had kids.<BR>\n" );
document.write( "Based on this, construct a 99% confidence interval for the proportion p of adult residents who are parents in this county.<BR>\n" );
document.write( "Answer in tri-inequality form.<BR>\n" );
document.write( "Answer as decimals, to 3 places.<BR>\n" );
document.write( "Express the same answer using the point estimate and margin of error.<BR>\n" );
document.write( "Answer as decimals, to 3 places. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #813263 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=813263\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a one-proportion z-interval<BR>\n" );
document.write( "half-interval for 99% is z(0.995)*sqrt(p*(1-p)/n)<BR>\n" );
document.write( "=2.576*sqrt(0.35*0.65/100)<BR>\n" );
document.write( "=0.1228, or 0.123<BR>\n" );
document.write( "so the 99%CI is (0.227, 0.477)<BR>\n" );
document.write( "or 0.227 < p < 0.473<BR>\n" );
document.write( "or 0.35+/-0.123 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );