In this task you will be given a list of numbers and you need to find the mean (average) of that list. The mean of a list can be found by summing every number in the list then dividing the result by the size of that list. The output should be rounded to 3 decimal places.

Example Input: [93.72, 13.366, -44.452, -29.011, 56.593, 5.272, -20.162, 160.282, 44.017]
Example Output: 31.069

Example Input: [-96.502, 12.006]
Example Output: -42.248

Example Input: [93.313, 229.534, 97.742, 249.167, 93.275, 65.841, -24.118, 57.312]
Example Output:
107.758