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: [78.368, 216.787, -96.687, 81.728, 119.928, 49.546, 155.834, -96.513]

63.624