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: [100.665, 40.782, 24.775, 206.105, 112.523, -96.309, 9.758, 149.054, 3.861, 235.974]

78.719