Investors & landlords

Going along with my example, I see TurboTax is calculating my mortgage interest deduction as 750K/(700K+1000K) or 44% ratio to the mortgage interest I paid (adjusted for what I allocated to the rental). I was expecting something closer to a 750K/1000K = 75% ratio. Is 44% approximately correct, or have I mis-entered something along the way? Thanks.