document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1155693>Question 1155693</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 265.9-cm and a standard deviation of 1.6-cm. For shipment, 30 steel rods are bundled together.\r<BR>\n" );
document.write( "\n" );
document.write( "Find the probability that the average length of a randomly selected bundle of steel rods is between 265.4-cm and 266.8-cm.<BR>\n" );
document.write( "P(265.4-cm < M < 266.8-cm) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #778405 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=778405\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> use a z-test where z=(xbar-mean)/sigma/sqrt(n)<BR>\n" );
document.write( "The denominator is the SE and is 1.6/sqrt(30)=0.292\r<BR>\n" );
document.write( "\n" );
document.write( "z=-0.5/0.292 and .9/.292 or between -1.71 and 3.08<BR>\n" );
document.write( "that probability is 0.9553. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );