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: [229.366, 136.878, -63.657, 77.734, 113.334, 130.379, 130.19, -51.455, -32.275, 112.56]

78.305