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.

[20.796, 39.383, -26.46, -27.224, 89.591, 87.502, 211.781, 127.87, 223.38]
82.958

[208.757, -63.857, 124.458, 25.069, -39.093, -85.924, 112.747]
40.308

[-71.731, 44.88, -17.857]

-14.903