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.
[-9.018, 244.418, 30.094, 116.769, -35.584, 8.008, 32.91, -74.622]