document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=135343>Question 135343</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A company that sells mail order systems has been planning inventory and staffing based on an assumption that the mean of their weekly sales is 180. The weekly sales are normally distributed. The company selects 10 weeks at random from the past year and obtains the data shown below.<BR>\n" );
document.write( "Weekly sales:\r<BR>\n" );
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document.write( "179   172   170    179   194<BR>\n" );
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document.write( "189   176   198    193   178\r<BR>\n" );
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document.write( "Set up the hypothesis test to test weather the sample mean is different from 185<BR>\n" );
document.write( "At the 0.05 significance, what can you conclude about the company's assumption?<BR>\n" );
document.write( "Treat as a large sample. <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 #99168 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=99168\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A company that sells mail order systems has been planning inventory and staffing based on an assumption that the mean of their weekly sales is 180. The weekly sales are normally distributed. The company selects 10 weeks at random from the past year and obtains the data shown below.<BR>\n" );
document.write( "Weekly sales: <BR>\n" );
document.write( "179 172 170 179 194 189 176 198 193 178 <BR>\n" );
document.write( "Set up the hypothesis test to test weather the sample mean is different from 185<BR>\n" );
document.write( "At the 0.05 significance, what can you conclude about the company's assumption?<BR>\n" );
document.write( "Treat as a large sample. <BR>\n" );
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document.write( "x-bar = 182.8 ; s = 9.87477..<BR>\n" );
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document.write( "Ho: u=185<BR>\n" );
document.write( "Ha: u Is not 185<BR>\n" );
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document.write( "Critical value for 2-tail test with alpha = 5%: z= +/- 1.96<BR>\n" );
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document.write( "Test statistic: z(182.8) = (182.8-185)/[9.87477/sqrt(10)] = -0.704523<BR>\n" );
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document.write( "Conclusion: Since test statistic is not in the reject interval, Fail<BR>\n" );
document.write( "to reject Ho.  The test gives statistical evidence the u=185<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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