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: [70.496, 183.122, 75.017, -19.287, 53.364, -12.389, 249.47, -88.484, 249.98, 35.226]
Example Output: 79.652

Example Input: [232.014, -52.265]
Example Output: 89.875

Example Input: [-50.073, -18.97, 30.239, -25.441, 62.189, 59.358]
Example Output:
9.55