In 2015, the average duration of long-distance telephone calls from a certain town was 3.9 minutes. A telephone company wants to perform a test to determine whether this average duration of longdistance calls has changed. Fifty calls, originating from the town, was randomly selected and the following summary minutes. ∑ ? = 205 ∑(? − ?̅) 2 = 56.43   c. Using the p value approach at the 1% level of significance, test whether the mean duration of long-distance calls from the town had increased

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A: The detailed solution is as follows below:

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