Which graph is best to display change over time across multiple data series?

• A. Line graph
• B. Stem and leaf plot
• C. Circle graph
• D. Bar graph

Answer: (A)

Tracking how values change over time across several data series is best shown with a line graph. It plots time on the horizontal axis and the measurement on the vertical axis, with each data series represented by its own line. The lines let you see trends, direction and rate of change, and how the series compare to one another at every point in time. Using different colors or styles for each line and a legend keeps the comparisons clear.

Stem-and-leaf plots are great for showing the distribution of a single dataset, not how values evolve over time. Pie charts (circle graphs) display parts of a whole at a single moment, so they don’t show changes over time or multiple time series. Bar graphs can compare values at specific moments, but they don’t convey continuous trends as smoothly as line graphs do.