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.

[21.007, 48.739, -49.831, -22.699]
-0.696

[211.892, 69.725, 110.579, 178.646, 32.595, 163.527, 229.039, -42.103, 51.631, 165.973]
117.15

[230.416, -57.729, 214.095, 137.62, 196.636, 137.956, 199.628, -57.559, 16.386, 186.284]
120.373