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: [-7.709, -56.36, -63.432, 53.588, 123.113, -61.531, 58.449, 36.598]

10.339