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: [93.8, 178.7, 115.271, 158.073, -51.09, 119.37, -14.279, 207.771, 227.777]

115.044