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: [117.882, -11.519, 138.961, -24.782, 12.95, -61.589, 240.254, 206.05, 105.082, 94.733]

81.802