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: [243.851, 197.293, -85.315, 158.097, 245.874, 85.687, -14.869, 96.95, 35.581]

107.017