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.
[16.214, 197.396, -39.565, 137.397, 224.751, 2.903, 230.131]