document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=359879>Question 359879</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A 15-minute Oil and Lube service claims that their average service time is no more than 15 minutes. A random sample of 40 service times was collected, and the sample mean was found to be 16.4 minutes, with a sample standard deviation of 3.2 minutes. Is there evidence to support, or to reject the claim at the alpha = 0.01 level? Perform an appropriate hypothesis test, showing the necessary calculations and/or explaining the process used to obtain the results </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #256777 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=256777\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A 15-minute Oil and Lube service claims that their average service time is no more than 15 minutes. A random sample of 40 service times was collected, and the sample mean was found to be 16.4 minutes, with a sample standard deviation of 3.2 minutes.<BR>\n" );
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document.write( "Is there evidence to support, or to reject the claim at the alpha = 0.01 level? Perform an appropriate hypothesis test, showing the necessary calculations and/or explaining the process used to obtain the results<BR>\n" );
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document.write( "Ho: u <= 15<BR>\n" );
document.write( "Ha: u > 15<BR>\n" );
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document.write( "t(16.4) = (16.4-15)/[3.2/sqrt(40)] = 2.7670<BR>\n" );
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document.write( "p-value = P(t> 2.7670 when df = 39) = tcdf(2.7670,100,39) = 0.0043<BR>\n" );
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document.write( "Since the p-value is less than 1%, reject Ho.<BR>\n" );
document.write( "The test results do not support the claim that u <=15 min.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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