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: [208.872, 59.574, 135.88, 152.251, -54.975, 116.537, 67.641]

97.969