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: [191.851, 52.413, 83.974, 10.09, -22.928, 3.772, 107.06, -14.847, 54.885]

51.808