document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1087398>Question 1087398</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A researcher wanted to determine if using an octane booster would increase gasoline mileage. A random sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks with the booster. Use the definitions of X1 and X2 as given in the table. Consequently, D = X1 X2.\r<BR>\n" );
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document.write( "X1: 21.2, 25.4, 20.9, 27.6, 22.8, 27.3, 23.4<BR>\n" );
document.write( "X2: 23.8, 25.6, 22.4, 28.3, 24.5, 28.8, 25.2\r<BR>\n" );
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document.write( "What critical value should be used at &#945; = 0.05?\r<BR>\n" );
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document.write( "2.447\r<BR>\n" );
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document.write( "2.365\r<BR>\n" );
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document.write( "1.943\r<BR>\n" );
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document.write( "1.895 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #701681 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=701681\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=\"black\" face=\"times\" size=\"3\"><BR>\n" );
document.write( "If you have your text book with you, then look up in the back of your book at the T table. Most, if not all, stats books will have reference tables in the appendix or in the chapter somewhere. I can't guarantee it will be there. All books are different.\r<BR>\n" );
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document.write( "If you can't find it in your book or you don't have your book with you, then you can use an online resource. I recommend using <a  rel=nofollow HREF= \"http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf\">this table</a>. That is the table I will be using.\r<BR>\n" );
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document.write( "We have n = 7 as the sample size. Therefore the degrees of freedom (df) is equal to df = n-1 = 7-1 = 6. Using the table I linked previously, locate the df = 6 row. Highlight everything in that row. Then mark the column that has \"one tail = 0.05\" up at the top. The intersection of this row and column leads to the value 1.943, which is the critical value. <BR>\n" );
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