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: [121.069, 12.661, 159.825, -39.645, 6.609, 156.735, 110.054, 112.875]

80.023