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: [-37.027, -31.987, 45.761, -22.372, -67.476, -51.455, -43.713, 15.122, 229.536]

4.043