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.

[54.908, 25.798]
40.353

[99.278, 72.353, -21.292]
50.113

[-11.899, 221.549, -15.365, -51.412, 85.7, -75.45, -25.543, 237.229]

45.601