document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1153503>Question 1153503</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed with a mean of 11 years and a standard deviation of 2 years.\r<BR>\n" );
document.write( "\n" );
document.write( "Find the probability that a randomly selected quartz time piece will have a replacement time less than 6 years? <BR>\n" );
document.write( "P(X < 6 years) = \r<BR>\n" );
document.write( "\n" );
document.write( "Enter your answer accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.\r<BR>\n" );
document.write( "\n" );
document.write( "If the company wants to provide a warranty so that only 0.9% of the quartz time pieces will be replaced before the warranty expires, what is the time length of the warranty? <BR>\n" );
document.write( "warranty =   years\r<BR>\n" );
document.write( "\n" );
document.write( "Enter your answer as a number accurate to 1 decimal place. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "please help </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #775766 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=775766\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "<(6-11)/2 OR <-2.50 and that probability is 0.0062\r<BR>\n" );
document.write( "\n" );
document.write( "z-value for 0.009 is -2.366<BR>\n" );
document.write( "-2.366*2=x-mean<BR>\n" );
document.write( "x=mean-4.732<BR>\n" );
document.write( "=11-4.732, or 6.268<BR>\n" );
document.write( "round to 6.3 years </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );