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: [-55.579, 201.522, -89.814, 92.507, 213.802, -13.352, 184.884, -47.663, -96.205, 143.467]

53.357