document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1187197>Question 1187197</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose a random sample of size 36 is drawn from a population with a mean of 277. If 91% of the time the sample mean is less than 279, what is the population standard deviation?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #818337 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=818337\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 91st percentile z=1.34<BR>\n" );
document.write( "z=(x-mean)/sigma/sqrt(36)<BR>\n" );
document.write( "1.34=(279-277)/sigma/6<BR>\n" );
document.write( "1.34=12/sigma<BR>\n" );
document.write( "sigma=8.95, the answer.<BR>\n" );
document.write( "The sd of the sample is 8.95/6 or 1.49<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );