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.

[-53.388, 31.309, 19.079, -16.926, 242.421, 210.599]
72.182

[151.151, 144.049, 217.252]
170.817

[246.122, 180.086, -2.65, 19.38]

110.735