Asimple random sample of 100 postal employees is used to test if the average time postal employees have worked for the postal service has changed from the value of 7.5 years recorded 20 years ago. the sample mean was = 7 years with a standard deviation of s = 2 years. assume the distribution of the time the employees have worked for the postal service is approximately normal. the hypotheses being tested are h0: ? = 7.5, ha: ?

: The average time postal employees have worked for the postal service is 7 years.

: The average time postal employees have worked for the postal service is not 7 years.

Step-by-step explanation:

We need to know the significance level to decide if the average time worked for the postal service has changed according to the the random sample of 100 postal employees working time.

Aur hypothesis would use two tailed critical region, sice the hypothesis is an equality.

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step-by-step explanation: