document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=624479>Question 624479</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 	Consider a couple having four children. We will consider this to be a binomial experiment with the number of trials n equal to 4.  Let us assume that success will mean a girl is born, and failure will mean a boy is born (don’t take it personally, guys).  The probability of success in any trial, then, is ½, or 0.5.  \r<BR>\n" );
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document.write( "	Write down the formula that gives the probability of Xsuccesses in the 4 trials in this binomial experiment. Simplify as much as possible.\r<BR>\n" );
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document.write( "	Use your formula to fill in a probability distribution table for X. It should look familiar!\r<BR>\n" );
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document.write( "X	p(X)<BR>\n" );
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document.write( "	\r<BR>\n" );
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document.write( "	Compute E(X), doing as little work as is needed.  Again, your answer should look familiar.\r<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 #392783 by </B><A HREF=/tutors/aboutme.mpl?userid=richard1234><B>richard1234(7193)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richard1234><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=richard1234><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=392783\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The probability distribution is given by\r<BR>\n" );
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document.write( "x---P(x)<BR>\n" );
document.write( "0---1/16<BR>\n" );
document.write( "1---4/16<BR>\n" );
document.write( "2---6/16<BR>\n" );
document.write( "3---4/16<BR>\n" );
document.write( "4---1/16\r<BR>\n" );
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document.write( "Where 1,4,6,4,1 is the fourth row of Pascal's triangle (which comes from a *binomial* expansion).\r<BR>\n" );
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document.write( "The expected value, E(x), is simply (1/2)(4) = 2.\r<BR>\n" );
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