According to the oxygen-hemoglobin dissociation curve, po2 in the lungs of 100 mm hg results in hb being 98% saturated. at high altitude, there is less o2. at a po2 in the lungs of 80 mm hg, hb would be saturated.

Hb would be 78.4% saturated.

Explanation:

This problem can be solved by using simple unitary method.

At 100 mm Hg pressure of oxygen, Hb is saturated by 98%

So, at 1 mm Hg pressure of oxygen, Hb is saturated by %

Hence, at 80 mm Hg pressure of oxygen, Hb is saturated by % or 78.4%

Therefore, at 80 mm Hg pressure of oxygen in the lungs, Hb would be 78.4% saturated.