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: [72.573, 198.024, 64.573, -98.444, -67.787, -46.476, -51.596, 139.0]

26.233