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: [185.65, 59.931, 2.895, -90.678, 23.13, 102.002, 146.218, -5.314, -39.25]

42.732