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: [190.775, 236.289, 153.003, 41.187, 169.006, -45.169, -75.314, 52.859, 9.214]

81.317