Hi Jose,
The I8 array formula seems to be working perfectly!
The other two formulas don't seem to be doing quite the right thing when I've pasted the formulas in.
The first one changes the value in H8 from 9.4 to 7.59 and I'm confident that 9.4 is the figure I'm looking for.
The formula for J8 changes the value from 124.2 to 2.4 and I'm confident that 124.2 is the figure I'm looking for.

Thank you very much for your help so far, you've been great.