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: [-18.796, 194.818]
Example Output: 88.011

Example Input: [96.706, 239.918, 73.299, 68.184, 233.512, -76.407]
Example Output: 105.869

Example Input: [79.978, -44.051, 200.217, 142.486, -89.194, 55.999, 165.078, -3.615, 0.12, -44.323]
Example Output:
46.27