Question 824477: A vice-president for a large corporation claims that salesmen are averaging no more than 15 sales contacts per week. (She would like to increase this figure) As check on her claim, 36 salesmen are selected at random, and the number of contacts is recorded for a single randomly selected week. The sample reveals a mean of 17 contacts and a variance of 9. Does the evidence contradict the vice-president’s claim?
Use = 0.50
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A vice-president for a large corporation claims that salesmen are averaging no more than 15 sales contacts per week. (She would like to increase this figure) As check on her claim, 36 salesmen are selected at random, and the number of contacts is recorded for a single randomly selected week. The sample reveals a mean of 17 contacts and a variance of 9. Does the evidence contradict the vice-president’s claim?
Use alpha = 0.05
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Ho: u <= 15 (claim)
Ha: u > 15
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x-bar = 17
test stat: z(17) = (17-15)/[9/sqrt(36)] = 2/(3/2) = 4/3
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p-value: p(z > 4/3) = normalcdf(4/3,100) = 0.0912
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Conclusion: Since the p-value is greater than 5%, fail to reject Ho.
The test results support the claim.
Cheers,
Stan H.
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