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: [-94.068, -52.758, 53.31, -5.178, -20.667, 100.51, 100.973, 168.318, 54.245, 210.951]
Example Output: 51.564

Example Input: [247.332, 97.053, 43.697, 51.168, -56.25, 163.444]
Example Output: 91.074

Example Input: [4.256, 246.003, 222.298, 50.991]
Example Output:
130.887