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.

[9.392, -80.549]
-35.579

[-51.625, 100.25, -75.262, -53.896]
-20.133

[194.494, -74.816, 50.491, 191.016, -84.334, 172.04]

74.815