document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1165740>Question 1165740</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Let y denote the number of people known personally who were victims of homicide within the past 12<BR>\n" );
document.write( "months. According to results from recent General Social Surveys, for a randomly chosen person in the United<BR>\n" );
document.write( "States the probability distribution of y is approximately P(0) = 0.91, P(1) = 0.06, P(2) = 0.02, and P(3) = 0.01.<BR>\n" );
document.write( "(a) Explain why it is not valid to find the mean of this probability distribution as (0 + 1 + 2 + 3)/4 = 1.5.<BR>\n" );
document.write( "(b) Find the correct mean of the probability distribution.<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 #790196 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=790196\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It is not correct because some values are larger than others, and calculating the mean requires that probabilities be taken into account. Zero is much more likely than 1, 2, or 3.\r<BR>\n" );
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document.write( "multiply the number of victims by the probability and add those results up<BR>\n" );
document.write( "0*.91=0<BR>\n" );
document.write( "1*0.06=0.06<BR>\n" );
document.write( "2*0.02=0.10<BR>\n" );
document.write( "3*0.01=0.03<BR>\n" );
document.write( "the total is 0.19 and that is the mean. </SPAN>\n" );
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