Answer:
No, because a mean is the average.
Step-by-step explanation:
Consider the following example:
The set is:
19, 23, 11, 31
if you add all these up you get 84.
Then you divide by 4 and get 21. So, 21 is the mean but, when you look at the set of numbers, 21 is not there. So, the same goes for any number, a number can still be the mean even if it is not in the set.