Answer:
The intralveolar pressure is 1 mmHg
Explanation:
The transpulmonary pressure is the difference between the alveolar pressure and the intrapleural pressure. It is this gradient between pressures that allows the air to flow during human ventilation.
Writing this into an equation it means that, Ptp = Palv - Pip, so from there we have Palv = Ptp + Pip, or Palv = 5 mmHg - 4 mmHg = 1 mmHg.