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: [-13.67, 239.672]

SOLUTION: 113.001

PROBLEM: [219.769, -36.26, 3.121, -22.5, 124.372]

SOLUTION: 57.7

PROBLEM: [130.625, -59.059, -26.75, 84.236, 200.451, 118.614, 216.98, 236.108, 167.719]

SOLUTION:
118.769