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: [109.109, -95.395, 5.04, 45.497, 56.443, -72.916]
Example Output: 7.963

Example Input: [-94.286, 148.737, 234.8, 148.972]
Example Output: 109.556

Example Input: [-44.471, 208.445, 208.318, -34.134]
Example Output:
84.54