Question 135008: 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 before after
Homer 19 12
Bart 6 18
Lisa 9 12
Marge 5 7
Maggie 9 14
Ned 8 17
Milhouse 11 9
Willie 11 17
Stu 11 12
Gill 7 7
Run a statistical hypothesis test and determine if the seminar significantly improved sales figures for the company.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 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 before after
Homer 19 12
Bart 6 18
Lisa 9 12
Marge 5 7
Maggie 9 14
Ned 8 17
Milhouse11 9
Willie 11 17
Stu 11 12
Gill 7 7
Run a statistical hypothesis test and determine if the seminar significantly improved sales figures for the company.
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These are dependent sample pairs because each pair related to a given
person's performance before and after the seminar.
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Enter your data;
Calculate the difference for each pair (before-after):
Run a t-Test on mean of the differences.
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Comment: If there is improvement before minus after should be negative.
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Ho: mu(differences) = 0
Ha: mu(differences) < 0 (Claim)
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d-bar(mean of the differences) = -2.9 ;s(diff) = 5.4661
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Critical Value for one-tail t-test with df=9 and alpha = 5%: t = -1.833
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Test statistic: t(-2.9) = (-2.9-0)/[5.4661/(sqrt(10)] = -1.6777
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Conclusion: Since test statistic is not in the rejection interval,
Fail to reject Ho; the seminar made no statistical difference in sales.
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Cheers,
Stan H.
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