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: [50.355, 52.337, 136.573, 85.214, 84.509, 217.871, 39.437, -75.544]

73.844