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: [78.466, 52.475, -48.487, 118.207, 125.374, 5.689, 211.198, 70.821]

76.718