document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1098403>Question 1098403</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the probabilities.<BR>\n" );
document.write( "1. The average life of a brand of automobile tires is 30 000 miles, with a standard deviation of 2000 miles. If a tire is selected and tested, find the probability that it will have the following lifetime. Assume the variable is normally distributed.<BR>\n" );
document.write( "a) between 25 000 and 29 000 miles<BR>\n" );
document.write( "b) between 28 000 and 31 000 miles<BR>\n" );
document.write( "c) between 32 500 and 34 500 miles\r<BR>\n" );
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document.write( "Please help me answer this. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #712763 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=712763\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd,  mean is 30000, sd is 2000<BR>\n" );
document.write( "z=(25000-30000)/2000=-2.5<BR>\n" );
document.write( "(29000-30000)/2=-0.5<BR>\n" );
document.write( "want z between -0.5 and -2.5, and from the calculator or table is 0.3023<BR>\n" );
document.write( "for b<BR>\n" );
document.write( "(-2000/2000)=-1 and (1000/2000)/2000=+0.5, and probability is 0.5328<BR>\n" );
document.write( "for c<BR>\n" );
document.write( "this is 2500/2000=+1.25 and 4500/2000=+2.5 and probability is 0.0317\r<BR>\n" );
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document.write( " </SPAN>\n" );
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