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: [30.716, 138.526, 134.886, -22.752, 174.381, 167.592, -55.509, 34.849, 178.013, 224.272]

100.497