# SAT Math Multiple Choice Question 856: Answer and Explanation

### Test Information

Question: 856

1. As the elevation above sea level increases, the corresponding air pressure decreases.A scatterplot comparing elevation, in feet, to air pressure, as a percent of sea levelpressure, is shown below.

Elevations above 8,000 meters are said to be in the "death zone," a range of elevationsin which oxygen levels are not high enough to sustain human life. What is the approximateair pressure (as a percent of sea level pressure) at the death zone threshold? (Note:1 meter ≈ 3.28 feet)

• A. 35%
• B. 50%
• C. 74%
• D. 92%

Explanation:

A

Difficulty: Medium

Category: Problem Solving and Data Analysis / Scatterplots

Strategic Advice: When information is presented in a graphic, always read the axis titles and labels carefully, including the units given.

Getting to the Answer: The death zone threshold is given in meters, but elevation is given in feet on the scatterplot. This means you'll need to convert the death zone threshold from meters to feet before doing anything else. Use the factor-label method to assemble a quick calculation:

Locate 26,240 ft on the x-axis of the scatterplot, and then identify the corresponding pressure on the y-axis, which is 35%. (A) is the correct answer.