Answer:
Add and Divide.
Mean = 84
Explanation:
Mean ( math word) and average (common usage word) tell us to ADD up the numbers in the list of data and DIVIDE by the number of pieces of data.
Here we add:
(80 + 84 + 88)
then divide by 3, because there's 3 numbers in this list.
(80 + 84 + 88)/3
= 252/3
= 84
The mean, or average is 84.