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: [172.084, 126.948, 90.757]

SOLUTION: 129.93

PROBLEM: [60.02, -66.628, -95.571, 114.26, 109.577, 141.08, 154.303, 228.454, 46.856, 7.365]

SOLUTION: 69.972

PROBLEM: [-21.995, 30.635, -47.589]

SOLUTION:
-12.983