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: [117.913, 21.456, 98.401, -32.801, -20.798, 182.745, 201.277]
Example Output: 81.17

Example Input: [79.978, -44.051, 200.217, 142.486, -89.194, 55.999, 165.078, -3.615, 0.12, -44.323]
Example Output: 46.27

Example Input: [-51.709, 7.971, 56.819, 147.653, 82.016, 33.283, 17.84, -45.317, 152.854, 6.908]
Example Output:
40.832

