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: [-2.772, 225.483, 211.749, 45.779, -82.623, 229.799, 107.783, 64.653]
Example Output: 99.981

Example Input: [-66.676, -7.063, -18.028, 13.407, 54.369, 148.394, -93.155]
Example Output: 4.464

Example Input: [34.842, 115.829, 62.148, 202.664, -84.382, 72.455, -0.305, -1.396, 112.898, 191.272]
Example Output:
70.602

