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: [211.23, 157.572, -97.072, 21.425, 195.219, -69.739, -17.559, 127.232, -61.403, 121.073]

58.798