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: [-84.771, 60.727, 165.566, 27.782, 159.929, 167.451, -64.15]
Example Output: 61.791

Example Input: [-43.529, 109.435, 160.949, 229.41, -36.645, -42.215, 139.786, 17.927, -93.902]
Example Output:
49.024