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: [66.647, 247.888, 55.318, 239.152, 111.398, 248.973, 231.76, 40.763]

155.237