document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=216036>Question 216036</A>: <I><SPAN STYLE=\"word-break: break-all;\"> solve the problem suppose that replacement times of washing machines are normally distributed with a mean of 9.3 years and a standard deviation of 1.1 years. Find the probability that 70 randomly selected washing machines will have a mean replacement times less than 9.1 years. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #163200 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=163200\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> suppose that replacement times of washing machines are normally distributed with a mean of 9.3 years and a standard deviation of 1.1 years. Find the probability that 70 randomly selected washing machines will have a mean replacement times less than 9.1 years.<BR>\n" );
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document.write( "The sample standard deviation is 1.1/sqrt(70) = 0.1315<BR>\n" );
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document.write( "Find the z-value of 9.1<BR>\n" );
document.write( "z(9.1) = (9.1-9.3)/0.1315 = -1.5209...<BR>\n" );
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document.write( "P(x<9.1) = P(z< -1.5209) = 0.06414...<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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