document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=907665>Question 907665</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The average price of personal computers manufactured by MNM Company is $1,400 with a standard deviation of $250.  Furthermore, it is known that the computer prices manufactured by MNM are normally distributed.  <BR>\n" );
document.write( "If 250 MNM computers were priced at or below $700.00, how many computers were produced by MNM? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #550486 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=550486\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z = (x-m)/sd<BR>\n" );
document.write( "x = 700 = price of 250 computers that were produced at that price or below.<BR>\n" );
document.write( "m = 1400 = average price of all computers that were produced.<BR>\n" );
document.write( "sd = 250 = standard deviation of all computers that were produced.\r<BR>\n" );
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document.write( "z = (x-m) / sd = (700 - 1400) / 250 = -700/250 = -2.8\r<BR>\n" );
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document.write( "z = -2.8\r<BR>\n" );
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document.write( "look up in the z-score table to see that a z-score of -2.8 has .00256 * area under the normal distribution curve to the left of it.\r<BR>\n" );
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document.write( "this means that .00256 of the computers were sold at a price at or below 700.\r<BR>\n" );
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document.write( "since there were 250 of them, then the total number of computers had to be 250 / .00256 = 100,000 computers were sold in all.\r<BR>\n" );
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document.write( "the actual answer you get will be determined by rounding.\r<BR>\n" );
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document.write( "some charts will show the area to the left of a z-score of -2.8 as .0026.\r<BR>\n" );
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document.write( "some calculators will be more accurate and show the z-score of -2.8 as .0025551906...\r<BR>\n" );
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document.write( "your answer will be somewhere around 100,000.\r<BR>\n" );
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document.write( "the z-score table i used is shown below:\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF=\"https://www.stat.tamu.edu/~lzhou/stat302/standardnormaltable.pdf\" target = \"_blank\">https://www.stat.tamu.edu/~lzhou/stat302/standardnormaltable.pdf</a>\r<BR>\n" );
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document.write( " </SPAN>\n" );
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