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: [89.062, 112.973, -83.064, 51.297, 52.458, 38.609, 211.119, 11.127, 158.686]

71.363