TASK 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.
PROBLEM: [-34.026, 86.773, 149.194, 228.14]

SOLUTION: 107.52

PROBLEM: [128.152, 95.16, 70.113, -16.853]

SOLUTION: 69.143

PROBLEM: [-51.218, -88.005, -60.468]

SOLUTION:
-66.564