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: [-95.173, 84.8, 35.182, 230.019, 129.892, -56.207, 11.839, 232.794, 214.094]

87.471