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: [-53.89, 13.76, -7.71, 206.702, -60.992, 185.008, -78.074, -37.252, -42.426, 224.717]

34.984