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: [82.437, 181.613, 19.202, -88.485, 34.915, 156.498, 125.766, -30.586, 174.67]

72.892