document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=271787>Question 271787</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A quiz cosists of 20 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the minimum passing grade is 70 % </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #198944 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=198944\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A quiz cosists of 20 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the minimum passing grade is 70 %<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Binomial Problem with n = 20 ; p = 1/4<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "70% of 20 = 14<BR>\n" );
document.write( "----<BR>\n" );
document.write( "P(x = 14) = 20C14(1/4)^14(3/4)^6 = 0.000025699...<BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "You could also find the probability<BR>\n" );
document.write( "that the person answered \"at least\" 14 questions correctly.<BR>\n" );
document.write( "P(14<= x <= 20) = 1 - binomialcdf(20,(1/4),13) = 0.000029512...<BR>\n" );
document.write( "===================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );