As the elevation above sea level increase, the corresponding air pressure decrease. A scatterplot comparing elevations, in feet, to air pressure, as a percent of sea level pressure, is shown balow.

Q. Air pressure is sometimes measured in inches of mercury. If sea level air pressure measures as 29.2 inches of mercury, what is the approximate difference, in inches of mercury, between the pressure at sea level and the pressure at the death zone threshold?

Options

A. `7.6`
B. `10.2`
C. `19.0`
D. `21.6`

Answer

C

Explanation

Difficult: Hard
Category: Problem Solving and Data Analysis/ Scatterplots
Strategic Advice: When questions are presented in a "set", you can sometimes use your answer from the previous question to answer the next one. However, make sure you answer the right question.
Getting to the Answer: You need to find the difference between the two indicated pressures. You know that the air pressure at the death zone threshold is approximately 35% of sea level air pressure from the previous question. Find 35% of 29.2 by multiplying: `0.35times29.2=10.2`. Be careful here, as the question asks for the difference between this pressure and sea level pressure, which is 29.2-10.2=19.0. (C) is the correct answer.