Thanks for the correction! And I concede to my teacher although, we didn't really had a debate. With her algorithm Q0 and Q4 exist but they don't divide the data, instead they serve as boundaries for the whole data. With my algorithm, Q4 would extend out of the true boundary of the data, which...
Ok so I started this debate with my teacher. It is about this formula for finding the Quartiles of grouped data. Let's take a look at this data:
With ungrouped data, 1 2 3 4 5 6 7 8 9 11 12, for example, we solve for Q1 as (at least that's what she taught us):
Q1 = 1(12) / 4
Q1 = 3...