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: [110.671, -22.006, 168.421, 152.718, 116.702, -26.669, -55.023, -72.932]
Example Output: 46.485

Example Input: [-19.13, 98.86, 158.686, 230.23]
Example Output: 117.161

Example Input: [101.045, 87.664, 7.351, -47.12]
Example Output:
37.235