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.

[120.236, 116.311, -13.268]
74.426

[85.011, -20.439, 195.195, 114.286]
93.513

[96.706, 239.918, 73.299, 68.184, 233.512, -76.407]

105.869