Use the graph on the right to answer the following questions.

a. Estimate the pressure at altitudes of
6 comma 000
6,000 feet,
18 comma 000
18,000 feet, and
29 comma 000
29,000 feet.
b. Estimate the altitudes at which the pressure is
24
24,
17
17, and
11
11 inches of mercury.
c. Estimating beyond the boundaries of the graph, at what altitude do you think the atmospheric pressure reaches 5 inches of mercury? Is there an altitude at which the pressure is exactly zero? Explain your reasoning.