Add them up:
8+7+7+5+3+2+2 = 34
Now count how many numbers there are:
I count 7 numbers
1. 8
2. 7
3. 7
4. 5
5. 3
6. 2
7. 2
Now divide 34 by 7
I get 4.857142857 or
That's the arithmetic mean. It's the same thing as
the ordinary average. That's not listed, so the problem
is botched.
Edwin