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: [30.99, 197.577, 211.905, 130.898, 10.106, -15.097, 139.3, 71.536, 114.755]

99.108