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: [129.69, -15.638, -59.745, 113.411, 3.389, -51.888, 155.336, 205.865]

60.052