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:
[-17.106, 23.8, -54.195, 233.82, -99.732, -68.488, 215.616]

Ex Output:
33.388

Ex Input:
[166.542, 216.326, 98.969, -96.779, 33.532]

Ex Output:
83.718

Ex Input:
[165.675, -73.496, 18.652, -84.822, 109.015, 229.08]

Ex Output:
60.684