How should you approach a Data Interpretation item that uses a line graph?

• A. Only memorize the final value.
• B. Read the axis labels.
• C. Identify the trend over time, read the axis labels, and compare the relevant data points to the question.
• D. Ignore axis labels.

Answer: (C)

Interpreting a line graph comes down to understanding how the quantity changes over time. Start by reading the axis labels so you know what is being measured and in what units, and what the time scale represents. Then look at the line to identify the overall trend—are values rising, falling, or fluctuating? Finally, pull the exact values or the differences for the data points relevant to the question and compare them.

This approach works because the axis labels tell you what the graph is about and the scale you’re reading from, while the trend shows the direction and pattern of change. Comparing the specific points asked in the question lets you determine the precise answer, whether you’re assessing growth, decline, or differences between two times.

Memorizing just a final value misses the bigger picture and the context of how the quantity moved over time, and ignoring axis labels can lead to misreading what’s being measured or the units involved.