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: [-4.604, 168.987, 102.481, 11.004, -5.365, 246.149, 7.486, 158.495]

85.579