In: Statistics and Probability
At the time she was hired as a server at the Grumney Family Restaurant, Beth Brigden was told, “You can average $77 a day in tips.” Assume the population of daily tips is normally distributed with a standard deviation of $4.48. Over the first 39 days she was employed at the restaurant, the mean daily amount of her tips was $78.46. At the 0.01 significance level, can Ms. Brigden conclude that her daily tips average more than $77? |
a. | State the null hypothesis and the alternate hypothesis. | ||||||||
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b. | State the decision rule. | ||||||||
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c. | Compute the value of the test statistic. (Round your answer to 2 decimal places.) |
Value of the test statistic: |
d. | What is your decision regarding H0? | ||||
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e. | What is the p-value? (Round your answer to 4 decimal places.) |
p-value: |
Solution :
This is the right tailed test .
The null and alternative hypothesis is ,
H0 : = 77
Ha : > 77
= 78.46
= 77
= 4.48
n = 39
= 0.01
Z = Z0.01 = 2.33
c.) Reject H1 if z > 2.33
Test statistic = z
= ( - ) / / n
= (78.46 - 77) / 4.48 / 39
= 2.04
Test statistic = 2.04
This is the right tailed test .
P(z > 2.04) = 1 - P(z < 2.04) = 1 - 0.9793 = 0.0207
P-value = 0.0207
= 0.01
P-value >
Do not reject H0