document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1085939>Question 1085939</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a study examining the effect of alcohol on reaction time, Liguori and Robinson (2001) found that even moderate alcohol consumption significantly slowed response time to an emergency situation in a driving simulation. In a similar study, researchers measured reaction time 30 minutes after participants consumed one 6-ounce glass of wine. Again, they used a standardized driving simulation task for which the regular population averages  m = 400 msec. The distribution of reaction times is approximately normal with  a = 40. Assume that the researcher obtained a sample mean of M = 422 for the n = 25 participants in the study.<BR>\n" );
document.write( "Are the data sufficient to conclude that the alcohol has a significant effect on reastion time? Use a two tailed test with a=0.01<BR>\n" );
document.write( "For this sample, the standard error is ______, and the value of the z-score is _____. With a=0.01, the boundaries of the critical region are _____. therefor, the data ______ sifficient to conclude that alcohol has significant effect on reaction time.\r<BR>\n" );
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document.write( "Does the data provide evidence that the alcohol significantly increased (slowed) reaction time? Use a one-tailed test with a=0.05\r<BR>\n" );
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document.write( "The data _____ provide evidence that the alcohol significantly (slowed) reaction time as the value of the z-score is _______ the boundary of the critical region of _____ obtained using one tailed test with a=0.05\r<BR>\n" );
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document.write( "Compute cohens d to estimate the size of the effect<BR>\n" );
document.write( "cohen's d = </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #700318 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=700318\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> SE=s/ sqrt(n).  I am assuming a=40 is std dev=40<BR>\n" );
document.write( "40/sqrt(25)=8, the standard error<BR>\n" );
document.write( "z-score is (422-400)/8=22/8=2.75<BR>\n" );
document.write( "with alpha=0.01, for a two sided test, z=+/-2.576<BR>\n" );
document.write( "The boundaries are 8*2.576=20.608<BR>\n" );
document.write( "Critical value or 99%CI=(379.392, 420.608)<BR>\n" );
document.write( "The data fall outside the boundaries providing evidence that alcohol significantly increased the reaction time.<BR>\n" );
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document.write( "with alpha=0.05, use 1.645, since it is one tail<BR>\n" );
document.write( "now the upper boundary is 8*1.645+400=413.16<BR>\n" );
document.write( "Now the evidence is insufficient to show that there was a difference.<BR>\n" );
document.write( "d=(M1-M2)/s=22/8=2.5 </SPAN>\n" );
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