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: [-55.127, 213.489, 163.679, -39.68, 23.105, 0.931, 135.822]

63.174