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: [-16.773, 193.623, 47.212, -55.477, 186.157, 155.293, 121.04, 132.907, 245.468]

112.161