What type of graph is used to track trends or changes over time?

A line graph is specifically designed to display trends or changes over time by connecting individual data points with a continuous line. This format allows viewers to easily identify patterns, trends, and fluctuations in the dataset as they progress along the time axis.

Line graphs are particularly effective for showing how a variable changes at regular intervals or across a certain length of time, such as daily stock prices, temperature changes over a week, or populations over the years. The clarity and simplicity of a line graph in representing continuous data make it a preferred choice for visualizing long-term trends.

In contrast, scatter plots visualize the relationship between two quantitative variables but do not inherently imply a trend over time. Heatmaps represent data in a matrix form with color coding, which is useful for showing correlations or distributions but lacks the temporal dimension. Multivariate data refers to datasets containing multiple variables, which can be visualized in various ways but doesn't specifically track changes over time like a line graph does.