Question 127447
Facing rising fax costs, a firm issued guidelines that transmissions of 10 pages or more should be done by 2 day mail instead. Exceptions are allowed, they want the average to be 10 or below. A firm examined 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? (b) Use excel to find the right tail – p value. 
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Ho: mu = 10
Ma: mu > 10
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one-tailed test with alpha=1%; critical value = 2.326
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Test Statistic: 
t(14.44) = (14.44-10)/(4.45/sqrt(35)) = 4.44*sqrt(35)/4.45 = 5.90
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The test statistic is greater than the critical value so reject Ho.
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The p-value = 0.0000000018236...
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Cheers,
Stan H.