Wouldn't a Reclassification with 4 classes do the trick? More on reddit.com

From some testing in my own document I can confirm that the "wrong" Q3 value is returned from Excels built in Quartile functions. I think the issue is that there are different ways to view Quartile, and Excel uses an odd method of interpolating instead of just taking the average of the numbers when a Quartile falls between them. Here's a link I found explaining the theory behind Excels Quartile calculation and why it would produce unexpected results in some cases. https://superuser.com/questions/343339/excel-quartile-function-doesnt-work To get the behavior you desire, you'll likely need to find a statistics package/add-in or make a custom function in VBA to use. More on reddit.com

You're getting 24 because there is an even number of data points in the quartile, so the Q3 value will be the average of the 2 middle points, in this case 23 and 25 ((23+25)/2). This is standard behavior and pretty much any calculator will do this, not to mention that it's the correct answer. More on reddit.com

You are not right. Or, maybe you are. There are hundreds of different ways to define procedures for finding percentiles/quartiles. Here is a listing of some of the common ones you encounter. Therefore, it isn't really interesting to talk about "right" or "wrong" ways of finding them. However, in an intro stats course, make sure you understand the way your instructor wants you to use. One thing that is for certain is that this particular example used in this class is idiotic. It is pedagogically very important to separate the two ideas: The numbers representing the ranks of the data in order (1st, 2nd, 3rd, etc.), from The numbers in the data themselves. Confounding the two by using fake data that are the same as the rank orders is guaranteed to confuse 1/2 the students. In other words, in reality the 1st quartile isn't "(3+4)/2" in the example you provided, but the mean of the 3rd and 4th values in the data set ordered from smallest to largest. More on reddit.com