document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1187842>Question 1187842</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A study is conducted to estimate the mean completion time of a task to within 2 minutes 36 seconds of the population mean. Suppose completion time is normally distributed with a standard deviation of 7 minutes 54 seconds. What minimum sample size is required at the 96.6% confidence level?\r<BR>\n" );
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document.write( "You must use a critical z value rounded to two (2) decimal places.\r<BR>\n" );
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document.write( "Minimum sample size required =  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #818857 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=818857\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> error is 156 seconds <BR>\n" );
document.write( "sd is 474 seconds<BR>\n" );
document.write( "z(0.983)=2.12<BR>\n" );
document.write( "error=z*s/sqrt(n)<BR>\n" );
document.write( "156=2.12*474/sqrt(n)<BR>\n" );
document.write( "sqrt(n)=2.12*474/156=6.44<BR>\n" );
document.write( "n=41.49 round to 42 </SPAN>\n" );
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