Zappos is an online retailer based in Nevada. One of their competitors, Amazon.c
ID: 3157023 • Letter: Z
Question
Zappos is an online retailer based in Nevada. One of their competitors, Amazon.com, would like to test the hypothesis that the average age of a Zappos employee is more than 36 years old. A random sample of 22 Zappos employees was found to have an average age of 38.1 years. The standard deviation for this sample was 4.1 years. Amazon would like to set = 0.025. The distribution is approximately normal.
A. The correct hypothesis statement for this hypothesis test would be
B. Determine the level of significance
C. Determine the rejection region
D. Determine the test statistic
E. Determine the p-value
Explanation / Answer
a)
Formulating the null and alternative hypotheses,
Ho: u <= 36
Ha: u > 36 [ANSWER]
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b)
Here, alpha = 0.025. [ANSWER]
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c)
As we can see, this is a right tailed test.
Thus, getting the critical t,
df = n - 1 = 21
Hence, by table/tchnology,
tcrit = + 2.078
Hence, reject Ho when t > 2.078. [ANSWER]
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d)
Getting the test statistic, as
X = sample mean = 38.1
uo = hypothesized mean = 36
n = sample size = 22
s = standard deviation = 4.1
Thus, t = (X - uo) * sqrt(n) / s = 2.402408072 [ANSWER]
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e)
Also, the p value is, as this is one tailed,
p = 0.012808429 [ANSWER]
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As P < 0.025, we REJECT THE NULL HYPOTHESIS.
There is significant evidence that the average age of a Zappos employee is more than 36 years old.
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