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: [157.14, 120.799, -55.651, -50.479, 89.067, 192.279, 57.227, 137.972]

81.044