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: [50.305, -51.73, -85.087, 155.745, 141.982, -21.159, -41.206, 132.518, 23.832]

33.911