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: [-42.956, 89.597, -60.477, 101.972, 77.479]
Example Output: 33.123

Example Input: [-12.392, 57.854, 59.291, -18.155, -94.56, 94.214, -38.912]
Example Output: 6.763

Example Input: [-74.278, 45.794]
Example Output:
-14.242