Definition: 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: [-8.774, 60.206, 87.285, 104.039, 150.203, 180.644, 173.336, 2.861, -46.764, 91.335]

79.437