document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=286569>Question 286569</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Use normal approximation to estimate the probability of getting less than 48 girls in 100 births. Assume that boys and girls are equally likely. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #207951 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=207951\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use normal approximation to estimate the probability of getting less than 48 girls in 100 births. Assume that boys and girls are equally likely.<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "binomial P(0<= x <=48) <BR>\n" );
document.write( "normal appox = P(-0.5<= x <=48.5)<BR>\n" );
document.write( "mean = np = 100(1/2) = 50<BR>\n" );
document.write( "std = sqrt(npq) = sqrt(50(1/2)) = sqrt(25) = 5<BR>\n" );
document.write( "----<BR>\n" );
document.write( "z(-0.5) = (-0.5-50)/5 = -10.1<BR>\n" );
document.write( "z(48.5) = (48.5-50)/5 = -0.3<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "P(-10.1<= z <=-.3) = 0.3821<BR>\n" );
document.write( "================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );