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: [202.411, 127.775, 165.721, -41.545, 113.127, 229.974, 111.13, 208.686, 92.744, 36.522]
Example Output: 124.654

Example Input: [152.683, 147.968, 62.877, -44.254, 4.344]
Example Output: 64.724

Example Input: [-47.462, 69.283, 176.536, -64.153, 144.242]
Example Output:
55.689