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.
[184.883, 31.746, 111.972, 67.031, 117.43, 32.534, 169.862, -51.339, 98.662]