document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1151501>Question 1151501</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose that 25% of the people in a certain population have low hemoglobin levels. The experiment is to choose 5 people at random from this population. Let the discrete random variable X be the number of people out of 5 with low hemoglobin levels.<BR>\n" );
document.write( "A. Find the probability distribution of X.<BR>\n" );
document.write( "B. Find the probability that at least 2 people have low hemoglobin levels.<BR>\n" );
document.write( "C.	 Find the probability that at most 3 people have low hemoglobin levels.<BR>\n" );
document.write( "D. Find the expected number of people with low hemoglobin levels out of the 5 people. <BR>\n" );
document.write( "E. Find the variance of the number of people with low hemoglobin levels out of the 5 people. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #773365 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=773365\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a binomial distribution with n=5 and p=0.25<BR>\n" );
document.write( "probability of 0 people being low is 0.75^5=0.2373<BR>\n" );
document.write( "of 1 is 5*0.25*0.75^4=0.3955<BR>\n" );
document.write( "Of 2 is 5C2*0.25^2*0.75^3=10*0.0625*.75^3=0.2637<BR>\n" );
document.write( "of 3 is 10*0.25^3*0.75^2=0.0879<BR>\n" );
document.write( "of 4 is 5*.25^4*.75=0.0146<BR>\n" );
document.write( "of 5 is 0.25^5=0.001\r<BR>\n" );
document.write( "\n" );
document.write( "at least 2 is 1-P(0,1)=1-0.6328=0.3672<BR>\n" );
document.write( "at most 3 is P(0,1,2,3)=0.9844<BR>\n" );
document.write( "E(X)=np=1.25<BR>\n" );
document.write( "V(X)=np(l-p)=1.25*0.75=0.9375 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );