Answer: 91.65
Part 1: You will need to find the average by adding 108, 72, and 95. This will give you 275. Now you divide the sum by the amount of numbers there are which is 3 numbers. 275/3 would be 91.6
Part 2: Now that you have all four numbers you should repeat the process, 108 + 72 + 95 + 91.6 which is 366.6 now divide by four, and you have 91.65.
Let me know if this was correct!