document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=135744>Question 135744</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I'm in an online class so there is no textbook, please help, thanks.\r<BR>\n" );
document.write( "\n" );
document.write( "A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was $5.12 with a standard deviation of $2.14. The means appear to be very close, but not the variances. At &#945; = .05, is there a difference<BR>\n" );
document.write( "in variances? Show all steps clearly, including an illustration of the decision rule.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #99487 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=99487\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was $5.12 with a standard deviation of $2.14. The means appear to be very close, but not the variances. At &#945; = .05, is there a difference<BR>\n" );
document.write( "in variances?<BR>\n" );
document.write( "-------------------------------<BR>\n" );
document.write( "Ho: s^2(matinee)-s^2(evening) = 0<BR>\n" );
document.write( "Ho: difference is not 0<BR>\n" );
document.write( "------------------------<BR>\n" );
document.write( "Test statistic: F= s1^2/s2^2 = (2.14)^2/3.02^2 = 0.5021...<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "Critical values for two-tail test with alpha-5%: <BR>\n" );
document.write( "left tail(F=0.44)<BR>\n" );
document.write( "right tail (F=2.27)<BR>\n" );
document.write( "------------------------------<BR>\n" );
document.write( "Conclusion: Since test stat is not in either rejection interval,<BR>\n" );
document.write( "Fail to reject Ho; variances are statistically the same, based<BR>\n" );
document.write( "on this test.<BR>\n" );
document.write( "====================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );