document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=449184>Question 449184</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Replacement times for CD players are normally distributed with a mean of 7.1 years and a standard deviation of 1.4 years. \r<BR>\n" );
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document.write( "	Find the probability that a randomly selected CD player will have a replacement time that exceeds 10 years.\r<BR>\n" );
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document.write( "Find the probability that a randomly selected CD player will have a replacement time of between 5 years and 7.1 years.\r<BR>\n" );
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document.write( "Two percent of all CD players are replaced in less than how many years?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #309040 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=309040\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Replacement times for CD players are normally distributed with a mean of 7.1 years and a standard deviation of 1.4 years. <BR>\n" );
document.write( "Find the probability that a randomly selected CD player will have a replacement time that exceeds 10 years.<BR>\n" );
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document.write( "z(10) = (10-7.1)/1.4 = 2.0714<BR>\n" );
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document.write( "P(x > 10) = P(z > 2.0714) = 0.01916<BR>\n" );
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document.write( "Find the probability that a randomly selected CD player will have a replacement time of between 5 years and 7.1 years.<BR>\n" );
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document.write( "z(7.1) = 0<BR>\n" );
document.write( "z(5)= (5-7.1)/1.4 = -1.5<BR>\n" );
document.write( "P(5< x <7.1) = P(-1.5< z <0) = 0.4332<BR>\n" );
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document.write( "Two percent of all CD players are replaced in less than how many years?<BR>\n" );
document.write( "Find the z-value with a left tail of 2%.<BR>\n" );
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document.write( "invNorm(0.02) = -2.0537<BR>\n" );
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document.write( "Find the corresponding \"year\" value using x = zs+u<BR>\n" );
document.write( "year = -2.0537*1.4+7.1 = 4.22 years<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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