document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1176919>Question 1176919</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Use the Normal Approximation to the Binomial Distribution to compute the probability of passing a true/false test of 30 questions if the minimum passing grade is 60% and all responses are random guesses. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #805052 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=805052\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> n=30 p=0.5<BR>\n" );
document.write( "mean is np=15<BR>\n" );
document.write( "variance is np(1-p)=7.5<BR>\n" );
document.write( "sd is sqrt (V)=2.74<BR>\n" );
document.write( "need to get 18 or more right<BR>\n" );
document.write( "z > (17..5-15)/2.74 or > 2.5/2.74 or 0.91<BR>\n" );
document.write( "that probability is 0.1814, using the normal approximation<BR>\n" );
document.write( "the exact value is 0.1808<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );