document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=925287>Question 925287</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Watch Corporation of Switzerland claims that its watches on average will neither gain nor lose time during a week. A sample of 18 watches provided the following gains (+) or losses (-) in seconds per week.<BR>\n" );
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document.write( "-.10<BR>\n" );
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document.write( "-.20<BR>\n" );
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document.write( ".00<BR>\n" );
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document.write( "-.32<BR>\n" );
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document.write( "-.30<BR>\n" );
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document.write( "-.23<BR>\n" );
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document.write( ".20<BR>\n" );
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document.write( ".25<BR>\n" );
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document.write( "-.10<BR>\n" );
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document.write( "-.37<BR>\n" );
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document.write( "-.61<BR>\n" );
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document.write( ".40<BR>\n" );
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document.write( ".30<BR>\n" );
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document.write( "-.64<BR>\n" );
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document.write( "-.10<BR>\n" );
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document.write( ".20<BR>\n" );
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document.write( "-.68<BR>\n" );
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document.write( "-.20<BR>\n" );
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document.write( "(a-1) <BR>\n" );
document.write( "Is it reasonable to conclude that the mean gain or loss in time for the watches is 0? Use the .02 significance level. At a level of .02 significance, we reject H0: &#956; = 0 if t < ______ or t > _____. (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.)<BR>\n" );
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document.write( "(a-2) The value of the test statistic is  _____ . (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.) <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 #561413 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=561413\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Ho:  &#956; = 0 <BR>\n" );
document.write( "Ha:  u &#8800; 0<BR>\n" );
document.write( "......<BR>\n" );
document.write( "n = 18<BR>\n" );
document.write( "sample mean = -.139  and s = .324<BR>\n" );
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document.write( "level of .02 significance.  Using z critical value<BR>\n" );
document.write( "ME = 2.326(.324/sqrt(18)  <BR>\n" );
document.write( "CI: -.178 < 0 < .178<BR>\n" );
document.write( "Note: small sample (DF = 17) ..may wish to use t-value( for critical value <BR>\n" );
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document.write( "test stat = -.139/(.324/sqrt(18)) = -1.82\r<BR>\n" );
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