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: [-59.409, 11.318, 60.798, 73.485, 72.784, -16.016, -33.438, -73.826, 66.933, -59.474]

4.316