document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=69967>Question 69967</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Among U.S. households, 24% have telephone answering machines. If a telemarketing campaign involves 2,500 households, find the probability that more than 650 have answering machines. \r<BR>\n" );
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document.write( "I get .2389 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #49867 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=49867\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I get 0.0096 or less than 1%.<BR>\n" );
document.write( "Converting 650 to a z-score I get:<BR>\n" );
document.write( "z(650)=[650-600]/sqrt(2500*0.24*0.76)=2.34<BR>\n" );
document.write( "which means that 650 is 2.34 standard <BR>\n" );
document.write( "deviations to the right of the mean which<BR>\n" );
document.write( "is 600.<BR>\n" );
document.write( "The probability of the number being greater<BR>\n" );
document.write( "than 650 is very small just as the probability<BR>\n" );
document.write( "of z being greater than 2.34 is very small.<BR>\n" );
document.write( "Hope this helps.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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