Answer: 5
Explanation:
We know that the standard deviation of the sampling distribution of the means is given by :_

Given : The average weekly earnings for employees in general automotive repair shops is
.
The standard deviation for the weekly earnings for such employees =
Now, the standard deviation of the sampling distribution of the means of average weekly earnings for samples of size
:-

Hence, the standard deviation of the sampling distribution of the means of average weekly earnings for samples of size 100 = 5