Instructions: 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: [19.66, 77.859, -40.301, 103.668, 88.788, 77.935, 157.158, 187.661]
Output:
84.054