document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1100861>Question 1100861</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Memory     80 GB    120 GB<BR>\n" );
document.write( "2 GB            15           55<BR>\n" );
document.write( "4 GB            10           20\r<BR>\n" );
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document.write( "A single computer is selected at random from the shipment.<BR>\n" );
document.write( "Let A be the event that the computer has an 80 GB hard drive.<BR>\n" );
document.write( "Let B be the event that the computer has a 120 GB hard drive.<BR>\n" );
document.write( "Let C be the event that the computer has 2 GBs of memory.<BR>\n" );
document.write( "Let D be the event that the computer has 4 GBs of memory.<BR>\n" );
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document.write( "What is the conditional probability P(C|B)?<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 #715555 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=715555\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br>It's rather hard to interpret the information as you present it.  Perhaps some formatting got lost in cyberspace....?<br><BR>\n" );
document.write( "Apparently we have a shipment of computers....<BR>\n" );
document.write( "15 with 80GB hard drive and 2GB memory<BR>\n" );
document.write( "55 with 120GB hard drive and 2GB memory<BR>\n" );
document.write( "10 with 80GB hard drive and 4GB memory<BR>\n" );
document.write( "20 with 120GB hard drive and 4GB memory<br><BR>\n" );
document.write( "The probability P(C|B) is the probability that C is true (the computer has 2GB memory), GIVEN THAT B is true (it has a 120GB hard drive).<br><BR>\n" );
document.write( "With this conditional probability, the sample space is only those computers that have a 120GB hard drive; that is 55+20 = 75 computers.<br><BR>\n" );
document.write( "The desired condition is that it is a computer with a 120GB hard drive AND a 2 GB memory; there are 55 of those computers.<br><BR>\n" );
document.write( "So P(C|B) is 55/75 = 11/15.<br><BR>\n" );
document.write( "Formally, the probability P(C|B) is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=P%28C+and+B%29%2FP%28B%29 ALIGN=MIDDLE  ALT=\"P%28C+and+B%29%2FP%28B%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "I personally find this hard to work with.  I find it much easier to think in terms of the sample space consisting of only those computers that satisfy condition B. </SPAN>\n" );
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