document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1141134>Question 1141134</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The average weight of 40 selected school buses was 4150 pounds.  The standard deviation was 480 pounds.  Find the 99% confidence interval of the true mean weight of all school buses.<BR>\n" );
document.write( "type of interval (z or t)<BR>\n" );
document.write( "estimate<BR>\n" );
document.write( "z or t value<BR>\n" );
document.write( "margin of error<BR>\n" );
document.write( "interval<BR>\n" );
document.write( "summary </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #762072 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=762072\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Point estimate is 4150 pounds<BR>\n" );
document.write( "use a t value with 39 df.is 2.71 for 99% CI\r<BR>\n" );
document.write( "\n" );
document.write( "half-interval or margin of error is t*s/sqrt(n)=2.71*480/sqrt(40)[=205.67<BR>\n" );
document.write( "interval is (3944, 4356) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );