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: [153.491, -55.827, 118.696, 73.152, 102.671, 230.126, 3.802, 125.444, 158.523]

101.12