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: [43.554, 122.733, 40.669, 163.641]
Example Output: 92.649

Example Input: [123.511, 37.811, 249.595, -25.324]
Example Output: 96.398

Example Input: [62.607, 81.072, 52.446]
Example Output:
65.375