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: [66.037, 30.958, 124.853]
Example Output: 73.949

Example Input: [126.136, -23.429, -25.125, -32.203, 36.405, 44.406, 147.828, -97.708, -69.793, 235.046]
Example Output: 34.156

Example Input: [-8.383, 119.676, 123.133, -58.683, 20.378, 164.54]
Example Output:
60.11