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: [72.562, 168.233, 57.896, -15.978, 205.269, 113.703, -35.753, 170.648, 128.816, 128.697]

99.409