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: [-71.951, -1.97, 148.323, 151.675, 32.313, 178.55, -82.134, 170.977, 130.153]

72.882