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: [-19.671, 72.292, -29.094, -98.837, -92.923, -43.113, 29.1, 213.153, -6.17, -33.778]

-0.904