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: [179.929, 180.162, -63.896, -56.366, 233.638]
Example Output: 94.693

Example Input: [247.332, 97.053, 43.697, 51.168, -56.25, 163.444]
Example Output: 91.074

Example Input: [167.002, 136.7, 206.887, 151.381, 15.938]
Example Output:
135.582