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: [-49.786, 238.124, -20.697, 32.014]
Example Output: 49.914

Example Input: [39.88, 58.489, 225.343, 105.008, 210.581, 35.577]
Example Output: 112.48

Example Input: [63.79, 201.051]
Example Output:
132.42