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.

[51.02, -71.125, 178.19, -7.234, -99.571, -17.215]
5.677

[21.953, -90.519, 92.624, 189.808, 130.57, -33.423, -16.126, 31.61, 119.582]
49.564

[247.121, 197.486]

222.304