document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=797258>Question 797258</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1.	We know that the probability of correctly responding to a multiple choice question while guessing is 0.25 if there are four answer choices.  Suppose a test has 20 questions.  We also know that correctly responding follows a binomial distribution for this test.<BR>\n" );
document.write( "what is the mean and standard deviation? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #481787 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=481787\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We know that the probability of correctly responding to a multiple choice question while guessing is 0.25 if there are four answer choices. Suppose a test has 20 questions. We also know that correctly responding follows a binomial distribution for this test.<BR>\n" );
document.write( "what is the mean and standard deviation?<BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "mean = np = 20*0.25 = 5<BR>\n" );
document.write( "std = sqrt(npq) = sqrt(5*0.75) = 1.9365<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" );