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: [127.522, 232.86, 46.593]
Example Output: 135.658

Example Input: [-4.749, 102.787, -45.229, 184.111, 221.888, 22.727, 20.887, 34.094]
Example Output: 67.065

Example Input: [195.437, 144.442, 139.299, 30.48]
Example Output:
127.414