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

Example Input: [204.235, -53.675, 201.303, 20.869]
Example Output: 93.183

Example Input: [195.584, -58.734, 66.928, 26.924, 245.906, 72.439, 103.563, 229.0, 43.957]
Example Output:
102.841