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: [-41.714, 218.588, 49.769, 142.519, 179.776, -99.226, 224.69, 191.642]
Example Output: 108.256

Example Input: [-58.447, 213.433, 187.859, 103.704]
Example Output: 111.637

Example Input: [-46.619, 194.249, 227.508, -47.478, 140.403, -28.808, 94.726, -84.299]
Example Output:
56.21