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: [106.518, 120.729, 162.408, -34.092, 132.2, 103.805, -60.777, 119.713, -23.522]

69.665