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: [69.958, -95.132, 3.101, -82.932, -24.957, 69.445, 147.916]

12.486