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: [175.015, 7.294, -30.146, 197.862, 76.557, 16.567, 176.301]
Example Output: 88.493

Example Input: [18.155, 114.069, 197.871, -99.696, 201.18]
Example Output: 86.316

Example Input: [-24.449, 190.879, 15.497, -18.605, -87.934, 42.644, 145.409]
Example Output:
37.634