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: [128.152, 95.16, 70.113, -16.853]

SOLUTION: 69.143

PROBLEM: [138.63, 106.759, 86.625]

SOLUTION: 110.671

PROBLEM: [-51.986, -35.463, 117.863, 85.376, 134.932, 22.087, -21.652, 229.811, -55.739, 215.347]

SOLUTION:
64.058