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.

[-55.198, 36.097, 190.132]
57.01

[192.74, 78.623, -5.937, 144.535]
102.49

[141.055, -38.856, 55.75]

52.65