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.

[84.142, -99.804]
-7.831

[-1.833, 218.553, -61.132, -19.027, 87.034]
44.719

[0.872, 13.005, 82.754, 94.817, 211.541, -81.096, 248.443]

81.477