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.
[1.965, 6.414, 41.32, 83.709, 20.44, 152.32, 15.974, 240.85, 69.194]