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: [-87.957, 120.743, -51.831, 155.86, 64.708, 199.518, 101.769, 42.557, -95.106]

50.029