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: [-72.554, 9.809, 27.09, 190.698]
Example Output: 38.761

Example Input: [-17.604, 15.108, 34.328, -94.608]
Example Output: -15.694

Example Input: [110.444, 23.089, -6.235, 112.579, 31.292, 190.857, 58.854, 148.587, 163.706, -5.219]
Example Output:
82.795