document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1177430>Question 1177430</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A certain cross of rat will result in white-black in the ratio of 8:5.?<BR>\n" );
document.write( "a) What is the probability that among 9 such offspring, 5 will be white? (accurate to 4 decimal places)\r<BR>\n" );
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document.write( "b) What is the expected number of black rats from part a)? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #806432 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=806432\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> probability of white is (8/13)<BR>\n" );
document.write( "assuming independence, this is 9C5 (8/13)^5*(5/13)^4. Use fractions for the exact value.<BR>\n" );
document.write( "=0.2433. <BR>\n" );
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document.write( "This is Np=9*5/13=45/13, or about 3.5 </SPAN>\n" );
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