Q&A for How to Calculate the Upper Quartile

Use the methods above to find the upper quartile. To find the lower quartile using the formula, use Q1 = 1/4(n+ 1), or enter 1 into the Excel function instead of 3.

The IQR can be calculated by subtracting the lower quartile from the upper.

Same as for a small group of numbers. Or better use script language like Matlab or Python to load the dataset and do the calculations.

Because the data is symmetrical, the mean will have the same value as the median. Also, the upper and lower quartiles will be equally far from the median. The interquartile range of 20 and lower quartile of 6 imply that the upper quartile is 26 (20+6=26). The median will be halfway between the upper and lower quartiles at 16. Again, because the data is symmetrical, the mean will also be 16.