document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=131436>Question 131436</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780072966930/algebrahomeworkh>Applied Statistics in Business & Economics</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> 9.78  Is this sample of 25 exam scores inconsistent with the hypothesis that the true variance is 64 (i.e., &#963; = 8)? Use the 5 percent level of significance in a two-sided test. Show all steps, including the hypotheses and critical values from Appendix E. Exams\r<BR>\n" );
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document.write( "80 79 69 71 74<BR>\n" );
document.write( "73 77 75 65 52<BR>\n" );
document.write( "81 84 84 79 70<BR>\n" );
document.write( "78 62 77 68 77<BR>\n" );
document.write( "88 70 75 85 84\r<BR>\n" );
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document.write( "I can't get the appendix to open on my online school.  I understand that I average the set of data, but don't understand what to do next. \r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #96014 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=96014\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Is this sample of 25 exam scores inconsistent with the hypothesis that the true variance is 64 (i.e., &#963; = 8)? Use the 5 percent level of significance in a two-sided test. Show all steps, including the hypotheses and critical values from Appendix E. Exams <BR>\n" );
document.write( "80 79 69 71 74<BR>\n" );
document.write( "73 77 75 65 52<BR>\n" );
document.write( "81 84 84 79 70<BR>\n" );
document.write( "78 62 77 68 77<BR>\n" );
document.write( "88 70 75 85 84 <BR>\n" );
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document.write( "Ho: sigma^2 = 64<BR>\n" );
document.write( "Ha: sigma^2 is not 64<BR>\n" );
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document.write( "alpha = 5%; critical Chi-Sq. values for 2-tail test with df=24:<BR>\n" );
document.write( "ChL = 12.401 ChR39.364<BR>\n" );
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document.write( "Test Statistic: Chi-Sq = (n-1)s^2/sigma^2 = 24*14.068^2/64^2 = 1.1596...<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "Conclusion:<BR>\n" );
document.write( "Test statistic is < 12.401 so Reject Ho.<BR>\n" );
document.write( "Sigma^2 is not 64<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );