document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1168625>Question 1168625</A>: <I><SPAN STYLE=\"word-break: break-all;\"> When two births are randomly​ selected, the sample space for genders is​ bb, bg,​ gb, and gg. Assume that those four outcomes are equally likely. Construct a table that describes the sampling distribution of the sample proportion of girls from two births. Does the mean of the sample proportions equal the proportion of girls in two​ births? Does the result suggest that a sample proportion is an unbiased estimator of a population​ proportion? For the entire​ population, assume the probability of having a boy is 1/2<BR>\n" );
document.write( "​, the probability of having a girl is 1/2<BR>\n" );
document.write( "​, and this is not affected by how many boys or girls have previously been born.\r<BR>\n" );
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document.write( "I have no clue how or what to do here. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #793257 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=793257\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> BB proportion 1/4<BR>\n" );
document.write( "BG proportion 1/4<BR>\n" );
document.write( "GB proportion 1.4<BR>\n" );
document.write( "GG proportion 1/4\r<BR>\n" );
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document.write( "E(X) where x is number of girls expected from 2 births. It is the sum of all the random variables x*p(x)<BR>\n" );
document.write( "=0*1/4=1/(1/4)+1(1/4)+2 (1/4)=1<BR>\n" );
document.write( "So the mean number of girls in 2 births is 1.\r<BR>\n" );
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document.write( "This suggests that the sample proportion is an unbiased estimate of the population proportion, because the expected value is the same as the population proportion (1/2) and 1 girl in 2 pregnancies.<BR>\n" );
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