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:
[15.799, 6.545, 101.018, -76.074, 51.291, -58.732, 131.857, -36.93, 131.423]

Ex Output:
29.577


Ex Input:
[220.962, 208.438, 236.846, 109.22, 52.06, -5.693, -89.2, 228.518]

Ex Output:

120.144