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: [-55.231, 40.654, -5.066, 187.427, 206.857, 126.982, -76.143, 210.762, 40.654, 76.568]

75.346