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: [182.441, 58.468, 209.229, 249.908, 32.346, 30.442]
Example Output: 127.139

Example Input: [82.748, 43.804, -13.469, 226.705, -7.478]
Example Output: 66.462

Example Input: [81.806, 201.553, 150.165, 89.324, -35.483]
Example Output:
97.473