document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=452695>Question 452695</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The following table lists the probability distribution of the number of refrigerators owned by all families in a city. Study the distribution and answer the questions.\r<BR>\n" );
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document.write( "x	  0	  1	  2	   3<BR>\n" );
document.write( "P(x)	.02	.28	.61	.09\r<BR>\n" );
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document.write( "The probability that a family owns:\r<BR>\n" );
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document.write( "a.	Exactly 3 refrigerators is: _______<BR>\n" );
document.write( "b.	At least 2 refrigerator is: _____ <BR>\n" );
document.write( "c.	Fewer than 3 refrigerators is: _____ <BR>\n" );
document.write( "d.  The mean of the distribution is &#61549; = ______ <BR>\n" );
document.write( "e.  The standard deviation of the distribution is &#61555; = _____ <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #311244 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=311244\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a.  0.09\r<BR>\n" );
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document.write( "b.  0.61 + 0.09 = 0.70\r<BR>\n" );
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document.write( "c.  1 - 0.09 = 0.91\r<BR>\n" );
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document.write( "d.  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=mu ALIGN=MIDDLE  ALT=\"mu\"   DISABLED_style= \"max-width:90%; height:auto;\" > = E(X) = 0*0.02 + 1*0.28 + 2*0.61 + 3*0.09 = 1.77\r<BR>\n" );
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document.write( "e.  variance = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sigma%5E2+=+E%28X%5E2%29+-+%28E%28X%29%29%5E2+=+0%5E2%2A0.02+%2B+1%5E2%2A0.28+%2B+2%5E2%2A0.61+%2B+3%5E2%2A0.09+-+1.77%5E2+=+0.3971 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "==> standard deviation = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sigma+=+sqrt%280.3971%29=++0.63 ALIGN=MIDDLE  ALT=\"sigma+=+sqrt%280.3971%29=++0.63\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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