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: [-78.176, -29.91, 25.823, 46.538, -30.419, 78.498, -50.155, -79.238, -47.249, -5.928]

-17.022