Definition: 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.
Input: [89.754, -12.667, 32.486, 212.806, 38.691, 125.914, 218.354, 129.832, 73.432, 5.113]

91.372