document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=870230>Question 870230</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A student randomly guesses at 20 multiple choice questions. Each question has 4 possible answers with only one being correct, and each is independent of every other question.<BR>\n" );
document.write( "find the probability that the student guesses 4 right, 3 correctly, more than 8 correctly, between 4 and 6 inclusively, would any of these be likely to occur? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #524804 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=524804\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> p(correct) = .25,  n = 20<BR>\n" );
document.write( "P(x = 4) = binompdf(20, .25, 4)= .1897<BR>\n" );
document.write( "P(x = 3) = P(x = 3) = binompdf(20, .25, 3) = .1339<BR>\n" );
document.write( "p(x > 8) = 1 - P(x = 7) = binomcdf(20, .25, 7) = .0409<BR>\n" );
document.write( "P( 4&#8804; x &#8804; 6) =  .7858 - .7749 = .0111<BR>\n" );
document.write( "P( x &#8805; 4 ) = 1 - binomcdf(20, .25, 3)= .7748<BR>\n" );
document.write( "P(x &#8804; 6) = binomcdf(20, .25, 6)= .7858 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );