document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=380341>Question 380341</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose the life of a certain brand of vacuum cleaner is normally distributed with a mean life of 12 years and a standard deviation of 4 years. A vacuum cleaner is randomly chosen. Find the probability that is will last between 6 to 12 years. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #269908 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=269908\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Suppose the life of a certain brand of vacuum cleaner is normally distributed with a mean life of 12 years and a standard deviation of 4 years. A vacuum cleaner is randomly chosen. Find the probability that is will last between 6 to 12 years.<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "z(6) = (6-12)/4 = -3/2<BR>\n" );
document.write( "---<BR>\n" );
document.write( "z(12) = (12-12)/4 = 0<BR>\n" );
document.write( "----<BR>\n" );
document.write( "P(6< x <12) = P(-3/2< z < 0) = 0.4332<BR>\n" );
document.write( "====================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );