Question 198568
Blockbuster is testing a new policy of waiving all late fees on DVD rentals using a sample of 10 randomly chosen customers. (a) At a-.10, does the data show that the man number of monthly rentals has increased? (b) Is the decision close? (c) Are you convinced? 
Customer No Late Fee Late Fee
1 14 10
2 12 7
3 14 10
4 13 13
5 10 9
6 13 14
7 12 12
8 10 7 
9 13 13 
10 13 9 
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These data are dependent pairs because each pair measures a "before"
and "after" for the same person.
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Make a list for each data set.  
Make a list of the difference (no late fee)-(late fee)
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Run a t-test on the difference of the 10 pairs.
mean of the difference = 2
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Ho: u(difference) = 0
H1: u(difference) > 0
Decision Rule: Reject Ho if the test statistic is greater than 1.383..
test statistic: t = 2.8604
p-value: 0.0094
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Conclusion: Since the p-value is less than 10%, reject Ho.
The test provides evidence that the mean of the differences
is not zero.
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Cheers,
Stan H.