document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=305683>Question 305683</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Eight college students were randomly divided into 2 groups of 4 each to test whether background music reduces studying capacity.  Each person was tasked with memorizing a list of 20 words.  Group 1 had music playing through earphones they were wearing.  Group 2 was not distracted.  The following are the number of words correctly remembered by each subject.  Test whether the music reduces studying capacity at a .05 level of significance.<BR>\n" );
document.write( "Group 1 -- DISTRACTED	Group 2 – NOT DISTRACTED<BR>\n" );
document.write( "Sample mean = 7<BR>\n" );
document.write( "Sample size = 4<BR>\n" );
document.write( "Sample std.dev. = 2.5	Sample mean = 14<BR>\n" );
document.write( "Sample size = 4<BR>\n" );
document.write( "Sample std.dev. = 3.5\r<BR>\n" );
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document.write( "3a) Direction = UPPER TAILED / LOWER TAILED / 2-TAILED (circle one)<BR>\n" );
document.write( "3b) P-value = ________________	<BR>\n" );
document.write( "3c) REJECT THE NULL or DO NOT REJECT THE NULL? (Circle one)<BR>\n" );
document.write( "3d) Can we conclude that music reduces studying capacity?   YES or NO (circle one)<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 #218910 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=218910\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Eight college students were randomly divided into 2 groups of 4 each to test whether background music reduces studying capacity.  Each person was tasked with memorizing a list of 20 words.<BR>\n" );
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document.write( "Group 1 had music playing through earphones they were wearing.  <BR>\n" );
document.write( "Group 2 was not distracted.  <BR>\n" );
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document.write( "The following are the number of words correctly remembered by each subject.  Test whether the music reduces studying capacity at a .05 level of significance.<BR>\n" );
document.write( "Group 1 -- DISTRACTED	Group 2 – NOT DISTRACTED<BR>\n" );
document.write( "Sample size = 4<BR>\n" );
document.write( "Sample mean = 7<BR>\n" );
document.write( "Sample std.dev. = 2.5<BR>\n" );
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document.write( "Group 2 --- NOT DISTRACTED<BR>\n" );
document.write( "Sample size = 4<BR>\n" );
document.write( "Sample mean = 14<BR>\n" );
document.write( "Sample std.dev. = 3.5\r<BR>\n" );
document.write( "\n" );
document.write( "3a) Direction = UPPER TAILED / LOWER TAILED / 2-TAILED (circle one)<BR>\n" );
document.write( "\"Reduces\" is the key word in the problem description:<BR>\n" );
document.write( "Ans: left-tail test<BR>\n" );
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document.write( "Note:<BR>\n" );
document.write( "Ho: u(music)-u(no music) = 0<BR>\n" );
document.write( "Ha: u(music)-u(no music) < 0 (\"no music\" helps)\r<BR>\n" );
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document.write( "3b) P-value = ________________<BR>\n" );
document.write( "Test Statistic: <BR>\n" );
document.write( "t(7-14)= (-7)/sqrt[2.5^2/4 + 3.5^2/4] = -3.2549<BR>\n" );
document.write( "p-value = P(t < -3.2549 when df = 5.4) = 0.0100<BR>\n" );
document.write( "Note: I used a 2-sample T test on a TI calculator<BR>\n" );
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document.write( "3c) REJECT THE NULL or DO NOT REJECT THE NULL? (Circle one)<BR>\n" );
document.write( "Since the p-value is less than 5%, reject Ho<BR>\n" );
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document.write( "3d) Can we conclude that music reduces studying capacity?<BR>\n" );
document.write( "   YES or NO (circle one)<BR>\n" );
document.write( "I'll leave that to you.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( "</TD></TR></TABLE>\n" );