document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=929919>Question 929919</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A company installs 5,000 light bulbs, each with an average life of 500 hours, standard deviation of 100 hours, distribution approximated by a normal curve.  Find the approximate number of bulbs that can be expected to last more than 400 hours?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #564652 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=564652\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean = 500hr, sd = 100hr, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=z+=+blue%28x+-+500%29%2Fblue%28100%29 ALIGN=MIDDLE  ALT=\"z+=+blue%28x+-+500%29%2Fblue%28100%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >    <BR>\n" );
document.write( "p(x > 400) = P( z >  -100/100) = normalcdf( -1, 100) = .84<BR>\n" );
document.write( ".84*5000 = 4200 bulbs can be expected to last more than 400 hours </SPAN>\n" );
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