First, find the mean.
Add all values and divide by the number of values:
(2 + 2 + 5 + 6 + 8 + 4 + 8 + 5 ) / 8 = 40/8 = 5
Calculate the positive distance of each value to the mean.
5 - 2 = 3
5 - 2 = 3
5 - 5 = 0
6 - 5 = 1
8 - 5 = 3
5-4= 1
8-5= 3
5 - 5 = 0
Sum all results and divide by the number of values
( 3 +3 + 0 + 1 +3 +1 +3 + 0) /8 = 14/8 = 1.75
MAD = 1.75