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: [189.707, 116.173, 33.761, 144.444, 207.418, 75.646, 212.298, -57.764]

115.21