document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=275990>Question 275990</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You are responsible for reliability of the electronic product that your company produces.  \r<BR>\n" );
document.write( "\n" );
document.write( " \r<BR>\n" );
document.write( "\n" );
document.write( "You decide to measure the time between equipment malfunctions over a one-year period.  Over that time you measured 40 electronic products.  You made 850 observations with a mean time between equipment failures of 550.35 hours, and a sample standard deviation of 207 hours.\r<BR>\n" );
document.write( "\n" );
document.write( " \r<BR>\n" );
document.write( "\n" );
document.write( "Your company supplies the electronic product to another company as a component to their product.  You guarantee an average time between malfunctions of 600 or more hours.\r<BR>\n" );
document.write( "\n" );
document.write( " \r<BR>\n" );
document.write( "\n" );
document.write( "Calculate a 99% confidence interval estimate for the mean time between malfunctions for all electronics of this type then interpret the results to assess whether your company will have a problem with this guarantee.  Explain your reasoning?\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #201267 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=201267\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You are responsible for reliability of the electronic product that your company produces. \r<BR>\n" );
document.write( "\n" );
document.write( "You decide to measure the time between equipment malfunctions over a one-year period. Over that time you measured 40 electronic products. You made 850 observations with a mean time between equipment failures of 550.35 hours, and a sample standard deviation of 207 hours. \r<BR>\n" );
document.write( "\n" );
document.write( "Your company supplies the electronic product to another company as a component to their product. You guarantee an average time between malfunctions of 600 or more hours. \r<BR>\n" );
document.write( "\n" );
document.write( "Calculate a 99% confidence interval estimate for the mean time between malfunctions for all electronics of this type then interpret the results to assess whether your company will have a problem with this guarantee. Explain your reasoning?<BR>\n" );
document.write( "---<BR>\n" );
document.write( "sample mean = 550.35<BR>\n" );
document.write( "standard error = E = invNorm(0.995)*207/sqrt(850) = 18.29<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "99% CI: 550.35-18.29 < u < 550.35+18.29<BR>\n" );
document.write( "99% CI: 532.06 < u < 568.64<BR>\n" );
document.write( "============================<BR>\n" );
document.write( "For your component your guarantee it too high.<BR>\n" );
document.write( "===================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );