Question 126127This question is from textbook Applied Statistics in Business and Economics
: I need your help please! Two other individuals and myself tried to solve this problem; however, the examples provided in this textbook are not very helpful.
Faced with rising fax costs, a firm issues a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages. (a) At the .01 level of significance, is the true mean greater than 10?
This question is from textbook Applied Statistics in Business and Economics
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Faced with rising fax costs, a firm issues a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages. (a) At the .01 level of significance, is the true mean greater than 10?
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Ho: mu <= 10
Ha: mu > 10
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alpha = 1%
Critical value: t=2.326
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Test statistic:
t(14.44) = (14.44-10)/[4.45/sqrt(35)] = 5.90
p-value = 5.758..*10^(-7) or almost zero.
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Conclusion: Reject Ho because p-value is much, much less than 1%
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The test gives strong statistical evidence that the mean is
greater than 10.
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Cheers,
Stan H.
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