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: [-71.88, -65.484, -58.071, 65.985, 220.421, -67.791, 55.046, -59.456]

2.346