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: [15.799, 89.814, 140.897, 53.358, 64.439, 80.492, 177.118, -74.065]

68.482