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: [2.81, 52.99, 55.279, 75.682, 73.835, 148.077, -54.162, 112.112]

58.328