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.

[-21.77, 172.703, -31.807, 129.587, 84.624, 14.279]
57.936

[-42.207, -46.667, 171.095]
27.407

[194.927, -64.069, 32.164, 180.576, 164.893, -95.655, 203.533, 165.079, 232.333]

112.642