I have a large array of numbers. These readings were taken every day for four months. One gadget is represented by each row. I must determine the trendline and disregard the outliers. I made an effort to determine the IQR, then the range, and finally a filter to remove outliers that fall beyond the range. the problem is that there are a lot of repetitive results so the q1 and the q3 could very easily be the same number. is there a way to select the central 90% of results in a range? let's say from [1,1,1,1,1,1,1,1,2,3,4,5,7,8,9,9,9,9,9,9] Select [1,1,1,1,1,1,1,2,3,4,5,7,8,9,9,9,9,9] to make life harder, I'd also like to be able to select the associated date with the day the measurement was taken. the dates are in a separate row.