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: [-47.024, 25.07, 65.069, 151.48, 205.827, 55.257, 231.689, 38.509, 142.422]

96.478