document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1168029>Question 1168029</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You need to estimate the proportion of United States citizens that support an increase in off-shore drilling. You take a random sample of 1851 citizens and find that 651 support an increase in off-shore drilling. Construct a 95% confidence interval for the population proportion.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #792633 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=792633\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> p hat=651/1851=0.352<BR>\n" );
document.write( "95% half-interval is z(0.975)*sqrt (phat*(1-phat)/n)<BR>\n" );
document.write( "=1.96* sqrt (0.352*0.648/1851)<BR>\n" );
document.write( "=+/-0.0218 or 0.22<BR>\n" );
document.write( "(0.330, 0.374)<BR>\n" );
document.write( "Use 0.373, with rounding, rather than 0.370.  </SPAN>\n" );
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