document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=743034>Question 743034</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the probability of getting at least 70 shoppers in our sample of 100 <BR>\n" );
document.write( "preferring Brand A if the true proportion of the population who prefers Brand A <BR>\n" );
document.write( "is 60%?\r<BR>\n" );
document.write( "\n" );
document.write( "Im not necessarily interested in the answer although it would be nice so I can check that the explanation is legit. Im just wondering how to do this type of question.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #452743 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=452743\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> What is the probability of getting at least 70 shoppers in our sample of 100 <BR>\n" );
document.write( "preferring Brand A if the true proportion of the population who prefers Brand A <BR>\n" );
document.write( "is 60%? <BR>\n" );
document.write( "--------<BR>\n" );
document.write( "p = 0.6<BR>\n" );
document.write( "std = sqrt[pq/n] = sqrt[0.6*0.4/100] = sqrt(0.24)/10 = 0.049<BR>\n" );
document.write( "----<BR>\n" );
document.write( "z(0.7) = (0.7-0.6)/0.049 = 2.041<BR>\n" );
document.write( "----<BR>\n" );
document.write( "P(x >= 0.7) = P(z > 2.041) = normalcdf(2.041,100) = 0.0206<BR>\n" );
document.write( "==================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );