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: [159.381, -84.046]

SOLUTION: 37.668

PROBLEM: [21.531, 221.161, -31.194]

SOLUTION: 70.499

PROBLEM: [94.324, -57.371, 218.035, 185.255, 174.01, 164.705, 115.56, 55.251, 43.573]

SOLUTION:
110.371