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: [-81.785, -44.121]
Example Output: -62.953

Example Input: [-78.42, 155.561, -99.439, 201.597]
Example Output:
44.825