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: [202.724, 129.438, -75.21, 114.102, 151.266]
Example Output: 104.464

Example Input: [24.119, 239.006, 239.873, 236.27, 134.34]
Example Output: 174.722

Example Input: [41.755, -49.024, 113.869]
Example Output:
35.533