document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1043436>Question 1043436</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The table to the right shows the results of a survey in which 2566 adults from Country&#8203; A, 1128 adults from Country&#8203; B, and 1085 adults from Country C were asked if human activity contributes to global warming. Complete parts&#8203; (a), (b), and&#8203; (c).\r<BR>\n" );
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document.write( "Adults who say that human activity contributes to global warming<BR>\n" );
document.write( "Country A<BR>\n" );
document.write( "68&#8203;%\r<BR>\n" );
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document.write( "Country B<BR>\n" );
document.write( "86&#8203;%\r<BR>\n" );
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document.write( "Country C<BR>\n" );
document.write( "93&#8203;%\r<BR>\n" );
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document.write( "(a) Construct a 99&#8203;% confidence interval for the proportion of adults from Country A who say human activity contributes to global warming. Round to three decimal places as needed.\r<BR>\n" );
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document.write( "(b) Construct a 99&#8203;% confidence interval for the proportion of adults from Country B who say human activity contributes to global warming. Round to three decimal places as needed.\r<BR>\n" );
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document.write( "(c) Construct a 99&#8203;% confidence interval for the proportion of adults from Country C who say human activity contributes to global warming. Round to three decimal places as needed. \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 #658586 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=658586\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The CI for each is of the form z*sqrt {(p)(1-p)/n}, and that is added/subtracted to the point estimate<BR>\n" );
document.write( "For A<BR>\n" );
document.write( "2.576*sqrt (0.68)(0.32/2566; the sqrt term is 0.0092, and the product is 0.024<BR>\n" );
document.write( "The CI is (0.656,0.704)<BR>\n" );
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document.write( "B has a smaller number, a higher probability, but n is a lot less, so expect a slightly larger CI<BR>\n" );
document.write( "2.576*sqrt(0.86)(0.14)/1128; sqrt term is 0.0103, and the product is 0.0266<BR>\n" );
document.write( "(0.833,0.886)<BR>\n" );
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document.write( "C has about the same number as B and a probability further from 50%, which will tend to lower the CI.<BR>\n" );
document.write( "2.576*sqrt{(0.93)(0.07)/1085}; sqrt term is 0.0077, and the product is 0.020<BR>\n" );
document.write( "(0.910,0.950)<BR>\n" );
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document.write( "Can use calculator STAT then TESTS, then 1-prop z-interval<BR>\n" );
document.write( "You need the number for each, and 68% of A is 1745, 86% of B is 970 and 93% of C is 1009.  These can be entered and the CI of 0.99 will be computed.\r<BR>\n" );
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