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: [169.216, -64.607, -82.083, 199.662, 35.641, 63.646, 148.436, 210.344, 13.78, 185.205]

87.924