document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=359609>Question 359609</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An automotive repair shop has determined that the average service time on an automobile is 130 minutes with a standard deviation of 26 minutes. A random sample of 40 automotive services is selected.\r<BR>\n" );
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document.write( "a. Compute the standard error of the mean. <BR>\n" );
document.write( "b. What is the probability that the sample of 40 automotive services will have a mean service time greater than 136 minutes? <BR>\n" );
document.write( "c. Assume the population consists of 400 automotive services. Determine the standard error of the mean. <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 #256604 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=256604\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An automotive repair shop has determined that the average service time on an automobile is 130 minutes with a standard deviation of 26 minutes. A random sample of 40 automotive services is selected. <BR>\n" );
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document.write( "a. Compute the standard error of the mean.<BR>\n" );
document.write( "SE = s/sqrt(n) = 26/sqrt(40) = 4.11<BR>\n" );
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document.write( "b. What is the probability that the sample of 40 automotive services will have a mean service time greater than 136 minutes?<BR>\n" );
document.write( "t(136) = (136-130)/4.11 = 1.4595<BR>\n" );
document.write( "P(x-bar >= 136) = P(t >= 1.4595 with df = 39) = 0.0762<BR>\n" );
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document.write( "c. Assume the population consists of 400 automotive services. Determine the standard error of the mean.<BR>\n" );
document.write( "SE = 26/sqrt(400) = 1.3<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. \r<BR>\n" );
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