document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1048101>Question 1048101</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 263 days and standard deviation 16 days. About 99.7% of all pregnancies last between what interval?=<BR>\n" );
document.write( " _____and_____days  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #663726 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=663726\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 263 days and standard deviation 16 days. <BR>\n" );
document.write( "About 99.7% of all pregnancies last between what interval?<BR>\n" );
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document.write( "Left tail = 0.003/2 = 0.0015<BR>\n" );
document.write( "Corresponding z-value = invNorm(0.0015) = -2.9677<BR>\n" );
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document.write( "Corresponding lower day limit = -2.9677*16+263 = 215.51 days<BR>\n" );
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document.write( "Corresponding upper day limit = +2.9677*16+263 = 310.48 days<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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