document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=142941>Question 142941</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was $30. A sample of 40 transactions this month revealed the mean amount spent was $33 with a standard deviation of $12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What is the p-value? Follow the five-step hypothesis testing procedure.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #104032 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=104032\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was $30. A sample of 40 transactions this month revealed the mean amount spent was $33 with a standard deviation of $12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What is the p-value? Follow the five-step hypothesis testing procedure. <BR>\n" );
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document.write( "Ho: u = 30<BR>\n" );
document.write( "Ha: u > 30<BR>\n" );
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document.write( "Critical Value for one-tail test with alpha-5% and n=40: z = 1.645<BR>\n" );
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document.write( "Test statistic: z(33) = (33-30)/[12/sqrt(40)] = 1.5811<BR>\n" );
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document.write( "p-value: P(1.5811 < z < 10) = 0.05692...<BR>\n" );
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document.write( "Conclusion: Since p-value is greater than 5%, Fail to reject Ho.<BR>\n" );
document.write( "The mean value has not increased.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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