document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1112737>Question 1112737</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the mean and variance for the following probability distribution\r<BR>\n" );
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document.write( "X	-1	-2	3	4<BR>\n" );
document.write( "P(X)	0.05	0.43	0.32	0.20 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #727795 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=727795\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean of x = expected value of x = summation i = 1 to 4 of x(i) * p(x(i))<BR>\n" );
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document.write( "mean = -1(0.05) + -2(0.43) + 3(0.32) + 4(0.20) = 0.85<BR>\n" );
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document.write( "variance = summation i = 1 to 4 of (x(i) - mean)^2) * p(x(i)) <BR>\n" );
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document.write( "variance = ((-1 - 0.85)^2 * (0.05)) + ((-2 - 0.85)^2 * (0.43)) + ((3 - 0.85)^2 * (0.32)) + ((4 - 0.85)^2 * (0.20)) = 7.1275<BR>\n" );
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