Mean Absolute Deviation (MAD) is found through the following steps
1) Find the mean. We add up the values and divide by the number of items.
2) Subtract each value from the mean and apply absolute value to ensure the result is not negative. This tells us how far each value is from the mean. Call these sets of distances set D.
3) Find the mean of set D, using the idea talked about in step 1. This will produce the MAD.
