document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=306102>Question 306102</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo.  Participants are randomly assigned to receive the new treatment or a placebo.  The outcome is pain relief within 30 minutes.  The data are shown in table 6-8\r<BR>\n" );
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document.write( "		         Pain relief	     no Pain relief	<BR>\n" );
document.write( "New medication    	      44		    76<BR>\n" );
document.write( "Placebo 	              21	            99 	<BR>\n" );
document.write( "    <BR>\n" );
document.write( "a. Generate a 95% confidence interval for the proportion of patients on the new medication who report pain relief.\r<BR>\n" );
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document.write( "b. Generate a 95 % confidence interval for the difference in proportions of patients who report pain relief. \r<BR>\n" );
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document.write( "how it calculated with 30 mins ? I'm still not understand.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #219170 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=219170\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo.  Participants are randomly assigned to receive the new treatment or a placebo.  The outcome is pain relief within 30 minutes.  The data are shown in table 6-8\r<BR>\n" );
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document.write( "		         Pain relief	     no Pain relief	<BR>\n" );
document.write( "New medication    	      44		    76<BR>\n" );
document.write( "Placebo 	              21	            99 	<BR>\n" );
document.write( "    <BR>\n" );
document.write( "a. Generate a 95% confidence interval for the proportion of patients on the new medication who report pain relief.<BR>\n" );
document.write( "sample proportion: 65/240 = 0.27<BR>\n" );
document.write( "standard error = E = 1.96*sqrt[0.27*0.73/240] = 0.056<BR>\n" );
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document.write( "95% CI: 0.27-0.056 < p < 0.27+0.056<BR>\n" );
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document.write( "b. Generate a 95 % confidence interval for the difference in proportions of patients who report pain relief.<BR>\n" );
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document.write( "sample proportion: (44/120)-(21/120 = 23/120 = 0.19<BR>\n" );
document.write( "standard error: 1.96*sqrt(0.19*0.81/120) = 0.07<BR>\n" );
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document.write( "95% CI: 0.19-0.07 < P < 0.19+0.07<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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