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: [-89.335, -64.615, 150.149, 29.267, -38.363, 126.852, 81.583, 48.857]

30.549