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: [187.902, 19.84, 159.537, 104.947, 192.383, 61.994, 187.71, 163.375, 66.199, -45.781]

109.811