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: [-71.836, -27.028, 181.838, -98.154, 246.742, 80.215, -91.229, 240.062, -24.786]

48.425