Definition: 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.
Input: [127.162, 172.53, -28.489, 54.044, 26.437, 83.874, -8.712, -50.953, 141.902]

57.533