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: [-29.579, 140.289, 149.431, -3.613, 227.44, -20.94, 80.001, -26.74, 117.711, 87.216]

72.122