document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=233878>Question 233878</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A local manufacturer wants to know how long to guarantee her toasters. A random sample of 16 toasters has an average lifespan of 1,000 hours with a standard deviation of 200 hours. If she doesn't want to replace any more than 10% of the toasters, for how long should she gaurantee her toasters? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #172542 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=172542\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A local manufacturer wants to know how long to guarantee her toasters. A random sample of 16 toasters has an average lifespan of 1,000 hours with a standard deviation of 200 hours. If she doesn't want to replace any more than 10% of the toasters, for how long should she gaurantee her toasters?<BR>\n" );
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document.write( "Find the z-value associated with a left tail of 10%.<BR>\n" );
document.write( "I used my TI-84 calculator to get:<BR>\n" );
document.write( "invNorm(0.10) = -1.2816<BR>\n" );
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document.write( "Find the \"x\" value associated with that z value<BR>\n" );
document.write( "using x = zs + u<BR>\n" );
document.write( "x = -1.2816*200 + 1000<BR>\n" );
document.write( "x = 743,69 hours<BR>\n" );
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document.write( "She should guantee them for around 745 hrs. of use<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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