Final answer:
The estimated VO2 max of the client on the summit of Mount Everest is 2.1 L/min.
Step-by-step explanation:
To estimate the client's VO2 max on the summit of Mount Everest, we need to consider the decrease in oxygen availability at high altitudes. Since VO2 max decreases by approximately 50% on the summit of Mount Everest compared to sea level, we can calculate the estimated VO2 max on the summit using the formula:
Estimated VO2 max = VO2 max at sea level * (1 - decrease percentage)
Plugging in the given values, we have:
Estimated VO2 max = 4.2 L/min * (1 - 0.50)
Estimated VO2 max = 4.2 L/min * 0.50
Estimated VO2 max = 2.1 L/min