document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1175402>Question 1175402</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The following reaction times (measured to the nearest second) were recorded for 8 drivers under two different conditions, without consuming alcohol and after consuming a controlled amount of alcohol.\r<BR>\n" );
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document.write( "Driver	        1	2	3	4	5	6	7       8<BR>\n" );
document.write( "Without Alcohol	3	4	3	3	6	5	3	5<BR>\n" );
document.write( "With Alcohol	3	5	4	6	7	4	4	7\r<BR>\n" );
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document.write( "(a) Test, at 1% level of significance, whether there is evidence that the alcohol  increases the reaction time. (12 marks)\r<BR>\n" );
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document.write( "(b) Do you think it is necessary to use the same driver for two different conditions above?  Explain your reasoning. (3 marks)<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 #801055 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=801055\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a paired t-test with df=7<BR>\n" );
document.write( "Ho: d=0<BR>\n" );
document.write( "Ha: d ne 0<BR>\n" );
document.write( "alpha is 3.499 p{reject Ho|Ho true}<BR>\n" );
document.write( "calculations<BR>\n" );
document.write( "differences are 0,1,1,3,1,-1,1,2<BR>\n" );
document.write( "mean is 1<BR>\n" );
document.write( "sd is 1.20<BR>\n" );
document.write( "t=(x bar-0)/s/sqrt(n)<BR>\n" );
document.write( "=1*sqrt(8)/1.20<BR>\n" );
document.write( "=2.35<BR>\n" );
document.write( "fail to reject Ho at the 1% level. p-value is 0.050.<BR>\n" );
document.write( "Insufficient evidence<BR>\n" );
document.write( "Using the same driver eliminates differences in metabolism and reaction time, and is a far better technique here. </SPAN>\n" );
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