document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1059126>Question 1059126</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In order to estimate the average daily down time, a manufacturer randomly sampled 41 days of production records and found a mean of 51.75 minutes and standard deviation of 7.9 minutes. A 90% confidence interval for the population mean is<BR>\n" );
document.write( "a. 83.21<BR>\n" );
document.write( "b. 84.32<BR>\n" );
document.write( "c. 85.57<BR>\n" );
document.write( "d. 81.93<BR>\n" );
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 #674202 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=674202\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The interval width is t(df=40,0.95)*7.9/sqrt(41); t-value will be 1.684<BR>\n" );
document.write( "interval is 1.684*7.9/sqrt (41)=2.078<BR>\n" );
document.write( "The CI is (49.67,53.83)<BR>\n" );
document.write( "None of the choices is a confidence interval; they are only single numbers, and none can be either part of the interval.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );