Question 139310
A manager hopes to improve the sales figures for 10 employees by sending them to a motivational seminar.  To test the effectiveness of this seminar, the manager compares the sales figures for each salesperson for the month immediately prior to the seminar and the month immediately following it.  

Employee                
Homer               
Bart 
Lisa
Marge
Maggie
Ned
Milhouse
Willie
Stu
Gill

Before
19
6
9
5
9
8
11
11
11
7

After
12
18
12
7
14 
17
9
17
12
7

Run a statistical hypothesis test and determine if the seminar significantly improved sales figures for the company.  
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You have before and after data for 10 employees.
These are dependent data pairs.
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Find the list of data differences (after-before).
Find the sum of those differences.
Find the mean(ud) and standard deviation(sd) of the set of differences.
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Ho: ud = 0
Ha: ud > 0
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Run a T-test on the sample mean (ud)
Critical value for one-tail t-test with alpha=5% and df=9: t=1.833
test statistic: t(2.9) = (2.9-0)/[5.466/sqrt(10)]= 1.6778
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Conclusion: Since test statistic is not in the rejection interval,
Fail to reject Ho. The seminar is not increase sales.
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Cheers,
Stan H.