Tuplet specified with a metric equation

Would anybody have any idea how one would possible engrave this:

By creating a line, I think:

Sure, but its not that I care about, It’s what on earth is the value to create the tuplet? Too much for my limited brain.

15:14y

(if you’re looking for 5 dotted 16th in the space of 7 16th, is that what you want?)