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: [-1.662, 16.544, 198.754, 214.723, 186.303, -19.17, 137.477, 137.445]

108.802