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: [183.579, 204.086, -55.275, -75.96, 144.491, 64.71, 180.828, 2.069, -28.085]

68.938