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

Example Input: [141.767, 179.216, -65.681, 220.694, 218.833, -91.372, -95.051, 175.189, 131.244]
Example Output:
90.538