"tzip123" wrote...
....
The example of a grade book is a bad example. I hope this example will
make things clearer. The data will look something like the following:

85 – 95 value of 1
78 – 87 value of 2

Clear as mud. Why should 86 give value 1 rather than value 2? Or is the
overlap just a typo on your part?

75 – 84 value of 3
90 – 100 value of 4
64 – 77 value of 5
58 – 68 value of 6
84 – 96 value of 7
62 – 70 value of 8
73 – 87 value of 9
etc.

More overlapping ranges. If you're selecting ranges top to bottom, you'll
never return value 8 (62-70) because the 58-68 range would capture 62-68 and
the 64-77 range would capture 68-70.

What are you trying to do? Does it have any rational mathematical basis?