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.

Ex Input:
[57.506, 172.357, 191.473, 131.849]

Ex Output:
138.296


Ex Input:
[245.466, 19.262, 199.878]

Ex Output:
154.869


Ex Input:
[169.836, 70.504, -68.824, -75.479, 112.803, -99.455]

Ex Output:

18.231