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: [-39.282, 206.858, 196.099, -35.2, 81.961, 211.819, 44.598, 97.441, -66.653, 66.857]

76.45