document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=855562>Question 855562</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A student is taking a multiple choice exam in which each question has five choices. Assuming<BR>\n" );
document.write( "that she has no knowledge of the correct answers to any of the questions, she has decided on a<BR>\n" );
document.write( "strategy in which she will place five balls (marked A, B, C, D, E) into a box. She randomly selects<BR>\n" );
document.write( "one ball for each question and replaces the ball in the box. The marking on the ball will determine<BR>\n" );
document.write( "her answer to the question.<BR>\n" );
document.write( "There are four multiple choice questions on the exam.<BR>\n" );
document.write( "(a) What is the probability that she will obtain full marks?<BR>\n" );
document.write( "(b) What is the probability that she will get at least three questions correct? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #515432 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=515432\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A student is taking a multiple choice exam in which each question has five choices. Assuming<BR>\n" );
document.write( "that she has no knowledge of the correct answers to any of the questions, she has decided on a<BR>\n" );
document.write( "strategy in which she will place five balls (marked A, B, C, D, E) into a box. She randomly selects<BR>\n" );
document.write( "one ball for each question and replaces the ball in the box. The marking on the ball will determine<BR>\n" );
document.write( "her answer to the question.<BR>\n" );
document.write( "There are four multiple choice questions on the exam.<BR>\n" );
document.write( "--------------------------<BR>\n" );
document.write( "Binomial Problem with n = 4 and p(correct) = 1/5<BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "(a) What is the probability that she will obtain full marks?<BR>\n" );
document.write( "P(x = 4) = (1/5)^4 = 0.0016<BR>\n" );
document.write( "--------------------------------<BR>\n" );
document.write( "(b) What is the probability that she will get at least three questions correct?<BR>\n" );
document.write( "P(3<= x <=5) = 1 - binomcdf(4,1/5,2) = 0.0272<BR>\n" );
document.write( "=================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );