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: [-22.74, -40.145, 54.964, 106.885, 43.546, 143.68, -36.221, -23.89, 70.981, -43.289]

25.377