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: [23.061, 0.487, -96.305, 212.958, 239.121, 149.408, 85.691]

87.774