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: [75.354, 232.628, -13.956, 88.21, 4.308, 222.534, 202.223, 79.989, 3.046]

99.371