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.
[228.567, 129.227, -43.675, 239.739, 45.633, 21.59, 203.835]