THF is miscible with water. That's easy to find. Isopropyl acetate is an organic compound, and is likely miscible with THF.
Now, does water and isopropyl acetate combine to form some sort of mixture that oils out in THF? That's always possible, but that's trivia -- people only know something like that if its a fun story to tell.
Note: you haven't troubled yourself to tell us in what proportions these solvents are mixed -- 1:1:1? Or a trace of isopropyl acetate in water with THF? Which do you mean? You won't easily find a reference with every proportion listed.