Answer:
322 mmHg
Explanation:
Step 1: Given data
Step 2: Calculate the partial pressure of oxygen (pO₂)
The total pressure of the gaseous mixture is equal to the sum of the partial pressures of the individual gases.
P = pHe + pN₂ + pO₂
pO₂ = P - pHe - pN₂
pO₂ = 756 mmHg - 229 mmHg - 205 mmHg
pO₂ = 322 mmHg