║First step║
Let's find the mean of Sherwin's homework scores. All we need to do is add up all the scores and divide by the amount of scores.
5+35+65+95= 200
200÷4=50
║Second step║
Find the distance away and ignore the minus signs.
5⇒45
35⇒15
65⇒15
95⇒45
║Third step║
Find the mean of the distances.
45+15+15+45
120÷4=30
The mean absolute deviation is 30.
Tell me if this helps!!