What is the mean absolute deviation of the data set? 12, 15, 7, 4, 9, 10, 9, 6

Here is an example:
Find the MAD of 2,4,6,8 Step 1 : Find the mean of the data : (2+4+6+8) / 4 = 20/5 = 4 Step 2 : Find the distance between each data and mean. Distance between 2 and 5 is 3 Distance between 4 and 5 is 1 Distance between 6 and 5 is 1 Distance between 8 and 5 is 3
Step 3 : Add all the distances : 3+1+1+3 = 8
Step 4 : Divide it by the number of data : 8 / 4 = 2 2 is the average absolute deviation.

It’s either a or c as the answer.