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: [-48.551, -24.867, -28.454, 118.464, 113.012, 113.214, 241.775, 19.157, 198.242]

77.999