document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1161649>Question 1161649</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The amount of Jen's monthly phone bill is normally distributed with a mean of $50 and a standard deviation of $9. What percentage of her phone bills are between $23 and $77? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #785251 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=785251\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "for $23<BR>\n" );
document.write( "z=(23-50/9=-3<BR>\n" );
document.write( "and<BR>\n" );
document.write( "z=(77-50)/9=+3<BR>\n" );
document.write( "probability of z between -3 and +3 is about 99.7%. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );