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: [222.198, -91.259, -78.475, 220.593, -58.21, -63.051, 77.786, 168.183]

49.721