document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140021>Question 1140021</A>: <I><SPAN STYLE=\"word-break: break-all;\">  random sample of 12 size AA batteries for toys yield a mean of 3.85 hours with standard deviation, 1.15 hours.\r<BR>\n" );
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document.write( "(a) Find the critical value, t*, for a 99% CI. t* = <BR>\n" );
document.write( "(b) Find the margin of error for a 99% CI.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #760541 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=760541\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> t (df=11,0.995)=3.106<BR>\n" );
document.write( "half-interval is margin of error<BR>\n" );
document.write( "t*s/sqrt(n)=3.106*1.15/sqrt(12)=1.03 </SPAN>\n" );
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