So, first add all the numbers together. 37.2 + 0 + 6.2 + 7.44 = 50.84
Now, however many numbers were added (which is 4 if you count them above) divide 50.84 by that. So, 50.84 divided by 4 (numbers in all) = 12.71
The 'mean absolute deviation' is 12.71
Hope this helps!! :)