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: [-45.479, 80.214, 114.961, 199.196, -67.547, 85.657, -40.835, 215.63]

67.725