document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=137429>Question 137429</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If you have a standard deviation of 86 pounds, a random sample of 90 and a mean breaking strength of 1850 pounds, find a 90% confidence interval for the true mean .<BR>\n" );
document.write( "Thanks, </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100548 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=100548\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If you have a standard deviation of 86 pounds, a random sample of 90 and a mean breaking strength of 1850 pounds, find a 90% confidence interval for the true mean .<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "The sample mean, x-bar, = 1850<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Comment: I'm using z=1.645 as the critical value for 90%<BR>\n" );
document.write( "You might want to use a t-value if you have one.<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Margin of error = E=1.645 = 14.9122<BR>\n" );
document.write( "---------<BR>\n" );
document.write( "90% CI: (1850-14.9122 < u < 1850+14.9122)<BR>\n" );
document.write( "==============================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );