Instruction
The arithmetic mean (or simply mean) is the sum of all observations in the dataset divided by the total number of observations. If we have an n-element dataset containing the values x_1,x_2,...,x_n then the arithmetic mean is defined by this formula:
If we have a three-element dataset consisting of the numbers 1, 2, and 3, then their sum is 6, and their arithmetic mean is 2.


