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: [41.702, 234.497, -89.388, 190.012, 139.982, 154.209, -33.875, 102.547, 35.48]

86.13