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: [72.066, 224.552, 85.005, 249.093, 20.946, 76.286, 56.95, 193.66, -27.553]

105.667