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: [120.623, 69.374, 47.751, 121.126, -98.66, -52.379, 172.802, -65.776, 164.938, -35.405]

44.439