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: [74.782, 172.791, -54.697, 117.477, -12.676, -16.392, 134.356, 101.245, -84.741]

48.016