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: [-91.294, 1.16, 9.709, 3.916, 64.354, -30.537, 87.655, -68.425, -43.299, 212.53]

14.577