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.
Input: [42.693, -17.294, 222.751, 14.94, 30.978, 26.505, 54.382, 143.499, -58.178, -68.823]

39.145