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: [-99.693, 185.037, 184.098, 105.53, -43.717, 127.516, 155.796, 89.64, 11.893]

79.567