That would make it a bit too strong, with too much acid. The closest of your previous tests was 1:3.24. Mixing 750 ml water and 250 ml HCL would be 1:3
It is a bit of a bummer that they did not use a standard normalization as the basis for their reagent.
If you want to improve your accuracy in mixing, you can get a volumetric flask set off of Amazon that contain various sizes of flasks. For instance, to mix 250 ml of HCL at 1:3.24, you would need a 750, 50 and 10 ml flask for the water. Filling a 10 ml flask would be a chore, so a syringe could replace that.