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: [230.416, -57.729, 214.095, 137.62, 196.636, 137.956, 199.628, -57.559, 16.386, 186.284]

120.373