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: [-78.675, -82.203, 209.779, -25.743, 193.886, 113.647, -35.136, 22.275]

39.729