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: [78.024, 17.922, 232.34, 191.572, -91.098, 5.456, 241.532, 146.535, 183.359, 218.778]

122.442