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: [156.072, -97.615, 183.405, 166.972, 2.398, -19.946, 162.579, 170.298, 47.56, 31.761]

80.348