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: [-96.833, -66.591, 16.497, 117.61, 155.714, -18.361, 51.448, -26.681, 145.481, -10.042]

26.824