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: [-50.208, 248.001, -92.993, -67.867, -25.771, 57.557]
Example Output: 11.453

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

Example Input: [234.272, 196.413, -92.425]
Example Output:
112.753