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: [-52.02, 100.638, -20.981, 195.412, -57.479, -8.839, 82.687, 230.54, 113.853]

64.868