After sales are selected outliers are removed from the potential sales by comparing the $/Acre for the land type that the subject has the most acres of. 


The $/Acre for the collection of sales is used to calculate an Interquartile Range (IQR). Anything that is outside 1.5 times the IQR +/- the mean (average) is removed. 


This is done on multiple passes, on each pass the single value that is the most extreme outlier is removed. Then the process is repeated calculating a new Interquartile Range and mean. The process stops once no outliers are removed.



https://www.mathworks.com/matlabcentral/cody/problems/42485