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: [42.384, 147.392, 5.188, 209.73, -69.962, 230.239, 240.38, 25.261, 62.139]

99.195