Answer:
MAD = 2
Explanation:
First We'll find the mean of data
Mean =

Mean = 4
Then, we'll find absolute deviation
=> |4-3| = 1
=> |4-2| = 2
=> |4-1| = 3
=> |4-1| = 3
=> |4-3| = 1
Now, taking the mean of these absolute deviations:
MAD =

MAD =

MAD = 2