document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=517747>Question 517747</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 4.	Strength tests carried out on samples of two yarns spun to the same count gave the following results:<BR>\n" );
document.write( "	Number in<BR>\n" );
document.write( "sample	Sample<BR>\n" );
document.write( "Mean	Sample<BR>\n" );
document.write( "variance<BR>\n" );
document.write( "Yarn A	4	50	42<BR>\n" );
document.write( "Yarn B	9	42	56\r<BR>\n" );
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document.write( "The strengths are expressed in pounds. Does the difference in mean strengths indicate a real difference in the mean strengths of the yarn?<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 #344919 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=344919\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Strength tests carried out on samples of two yarns spun to the same count gave the following results:<BR>\n" );
document.write( "	Number in sample	Sample Mean	Sample variance<BR>\n" );
document.write( "Yarn A	4	             50	               42<BR>\n" );
document.write( "Yarn B	9	             42	               56\r<BR>\n" );
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document.write( "The strengths are expressed in pounds. Does the difference in mean strengths indicate a real difference in the mean strengths of the yarn?<BR>\n" );
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document.write( "Ho: uA - uB = 0<BR>\n" );
document.write( "Ha: uA - uB is not 0 (claim)<BR>\n" );
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document.write( "Sample mean: 50-42 = 8<BR>\n" );
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document.write( "I ran a 2SampleTtest on my TI-84 to get:<BR>\n" );
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document.write( "test stat: t = 1.9563<BR>\n" );
document.write( "p-value: 0.0930<BR>\n" );
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document.write( "Conclusion: Since the p-value is greater than 5%,<BR>\n" );
document.write( "fail to reject Ho at the 5% level of significance.<BR>\n" );
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document.write( "The test results do not support the claim.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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