document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1143166>Question 1143166</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The pregnancy length in days for a population of new mothers can be approximated by a normal distribution with a mean of 271 days and a standard deviation of 7 days. \r<BR>\n" );
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document.write( "A. What is the minimum pregnancy length that can be in the top 13% of pregnancy lengths?<BR>\n" );
document.write( "B. What is the maximum pregnancy length that can be in the bottom 9% of pregnancy lengths?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #763982 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=763982\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> For the top 13% of lengths the z value is +1.127<BR>\n" );
document.write( "z=(x-mean)/sd<BR>\n" );
document.write( "1.127=(x-271)/7<BR>\n" );
document.write( "x=271+7.889  or 278.9 days for minimum length\r<BR>\n" );
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document.write( "For the bottom 9% it will have a z=-1.34<BR>\n" );
document.write( "The calculations will show 261.6 days \r<BR>\n" );
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document.write( "on calculator, 2nd VARS 3 for inv-norm<BR>\n" );
document.write( "type in decimal (so top 13% is 0.87 and bottom 9% is 0.09), then comma, then mean, then comma, then sd, then ENTER. </SPAN>\n" );
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