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: [89.53, 164.022, 246.192, -98.857, -61.39, -32.699, 120.685, 121.712]

68.649