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: [-12.204, 191.67, 75.601, 160.725, -26.397, -19.227, 10.614, -21.064, 39.502]

44.358