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: [182.441, 58.468, 209.229, 249.908, 32.346, 30.442]
Example Output: 127.139

Example Input: [29.292, 193.26, -48.646]
Example Output: 57.969

Example Input: [28.138, 41.76, -20.597, 60.157, 148.058, -74.272, -76.477, 38.343, 227.036, 141.991]
Example Output:
51.414