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: [148.383, 51.114, -14.07, 246.557, 231.575, -75.815, 180.515, 158.734, 57.834, 197.967]

118.279