1. Mean Absolute Deviation
M.A.D.
Mean Absolute Deviation

2. Why are you so mad????
The Mean Absolute Deviation tells us how far, on average, all values are from the middle.
Lets pretend you have taken 5 tests and want to find your mean absolute deviation. Here’s what you’ll do…

3. Mean 1st find the mean of the data 80 75 95 100 65 8 3 65 75 80 95
+100 5
415
-40 15
-15
415

4. Absolute
2nd find the DIFFERENCE between the mean and ALL pieces of the data! 80 75 95
100 65 83
-80 83
-75 95
-83
100
-83 83
-65 3 8 12 17 18

5. deviation 3rd find the MEAN of the NEW data!!! 3 8 12 17 +18 1 1 5 58-5 08 58
-05 3

6. Practice
Below are the maximum speeds of 8 roller coasters (mph) find the MAD. 58 88 40 60 72 66 80 48 8
=64

7. Now you know the mean, find the deviation (subtract mean and data)
Find the difference between these numbers and 64

8. Finally find the mean of the new data 8
= 12 ½