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: [-94.827, -4.806, 33.138, 11.562, -68.261]
Example Output: -24.639

Example Input: [116.268, 173.27, 228.827, 52.695, 66.445, -34.051, 152.137]
Example Output: 107.942

Example Input: [37.259, 208.225, 95.819, 205.221, 164.82, 101.837, -95.921, 112.447]
Example Output:
103.713