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: [-71.118, 160.927, 230.116, -26.655, -4.297, 64.272, 72.304, 41.517, 242.068]
Example Output: 78.793

Example Input: [-98.148, 101.327, 2.274, -17.364, 105.751]
Example Output:
18.768