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: [-92.0, 108.814, 164.207, 94.26, 33.74]
Example Output: 61.804

Example Input: [185.594, 89.215, 19.941, 23.299, 47.251]
Example Output: 73.06

Example Input: [-47.825, 2.521, -62.863, 8.438, 210.92, 95.93, -95.671]
Example Output:
15.921