document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=483269>Question 483269</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a clinical trial 250 patients are randomly assigned to receive either a proposed stroke prevention medication ( ) or a placebo ( ) and are followed over the course of a 5-years study period. These results are given in the following table:\r<BR>\n" );
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document.write( "Treatment Group	Event<BR>\n" );
document.write( "	Stroke	No Stroke	Total<BR>\n" );
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document.write( "12	108	120<BR>\n" );
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document.write( "28	102	130<BR>\n" );
document.write( "Total	40	210	250\r<BR>\n" );
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document.write( "a.	Estimate the risk of stroke comparing those on the medication to those on placebo and interpret the result.<BR>\n" );
document.write( "b.	Interpret your result in part a.<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 #330744 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=330744\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In a clinical trial 250 patients are randomly assigned to receive either a proposed stroke prevention medication ( ) or a placebo ( ) and are followed over the course of a 5-years study period. These results are given in the following table:\r<BR>\n" );
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document.write( "                                                                    <BR>\n" );
document.write( "Treatment Group	Event<BR>\n" );
document.write( "Stroke	No Stroke	Total<BR>\n" );
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document.write( "::::::12	108	120<BR>\n" );
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document.write( "::::::28	102	130<BR>\n" );
document.write( "Total	40	210	250\r<BR>\n" );
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document.write( "I'll assume the \"12\" refers to the treatment group and<BR>\n" );
document.write( "the 28 is the not-treatment group.<BR>\n" );
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document.write( "So p-hat = 12/120  = 0.10 for the treatment group<BR>\n" );
document.write( "and p-hat = 28/130 = 0.22 for the non-treatment group<BR>\n" );
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document.write( "Ho: p1-p2 = 0<BR>\n" );
document.write( "H1: p1-p2 < 0<BR>\n" );
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document.write( "test stat: (0.10-0.22)/sqrt[(0.1*0.9/120)+(0.22*0.78/130)] = -2.6375<BR>\n" );
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document.write( "p-value = P(z < -2.6375) = 0.0042<BR>\n" );
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document.write( "Conclusion: Since the p-value is less than 1%, reject<BR>\n" );
document.write( "Ho at the 1% significance level.<BR>\n" );
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document.write( "a.	Estimate the risk of stroke comparing those on the medication to those on placebo and interpret the result.<BR>\n" );
document.write( "b.	Interpret your result in part a.<BR>\n" );
document.write( "The non-treatment group is twice as liable have a stroke.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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