document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1050926>Question 1050926</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I really need help with this problem:\r<BR>\n" );
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document.write( "You are conducting a study to see if students do better when they study all at once or in intervals. One group of 12 participants took a test after studying for one hour continuously. The other group of 12 participants took a test after studying for three twenty minute sessions. \r<BR>\n" );
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document.write( "The first group had a mean score of 75 and a variance of 120. The second group had a mean score of 86 and a variance of 100.\r<BR>\n" );
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document.write( "a. What is the calculated t value? Are the mean test scores of these two groups significantly different at the .05 level?\r<BR>\n" );
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document.write( "b. What would the t value be if there were only 6 participants in each group? Would the scores be significant at the .05 level?\r<BR>\n" );
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document.write( "Thank you so much for your help!<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 #666558 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=666558\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> One group of 12 participants took a test after studying for one hour continuously. The other group of 12 participants took a test after studying for three twenty minute sessions. <BR>\n" );
document.write( "The first group had a mean score of 75 and a variance of 120. <BR>\n" );
document.write( "The second group had a mean score of 86 and a variance of 100. <BR>\n" );
document.write( "a. What is the calculated t value? <BR>\n" );
document.write( "Are the mean test scores of these two groups significantly different at the .05 level?<BR>\n" );
document.write( "t(75-86) = (-11)/sqrt[(120/12)+(100/12)] = -2.5690<BR>\n" );
document.write( "p(value) = 2*P(t< -0.6 when df = 12-1) = 2*tcdf(-100,-2.5690,11) <BR>\n" );
document.write( "= 2*0.013 = 0.026<BR>\n" );
document.write( "Since the p-value is < 5%, reject equality; the scores are significantly <BR>\n" );
document.write( "different<BR>\n" );
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document.write( "b. What would the t value be if there were only 6 participants in each group? Would the scores be significant at the .05 level?<BR>\n" );
document.write( "I'll leave that to you.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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