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.

Input: Consider Input: [21.531, 221.161, -31.194]

Output: 70.499


Input: Consider Input: [197.424, 44.178, 136.316, 246.48, 98.472, -31.327, 41.411]

Output: 104.708


Input: Consider Input: [-39.897, -17.803]


Output: -28.85


