A nurse from the local health department asks the infection preventionist to help develop a graph to display statewide tuberculosis cases. The trend has been increasing and they want the graph to be dramatic. What type of graph would be best suited to this task?

• A. Histogram
• B. Line graph
• C. Bar chart
• D. Pie chart

Answer: (A)

Showing how cases change over time needs a graph that links data points in their temporal order. A line graph does this best because it connects consecutive time points, making the trajectory—whether rising, falling, or fluctuating—clear at a glance. It lets you see the rate of increase and any sharp spikes, which is exactly what a dramatic increasing trend requires.

A histogram, by contrast, displays how often values fall into different value ranges and does not depict changes over time, so it wouldn’t reveal the trend in statewide tuberculosis cases. A bar chart can compare values across discrete time periods, but it’s less effective for illustrating continuous change over time since the bars don’t inherently show a smooth trajectory. A pie chart shows proportions of a whole at a single point in time, not a trend.

So for displaying an increasing trend in statewide tuberculosis cases, a line graph is the most informative choice.