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: [112.026, 20.03, 73.595, -24.957, 185.718, 36.43, 206.024]
Example Output: 86.981

Example Input: [127.703, -82.203, 53.438]
Example Output: 32.979

Example Input: [-43.959, 161.939]
Example Output:
58.99