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.
[-4.969, 232.548, 81.586, 13.448, -85.528, -1.661, -76.971]