3) __________ are used to compare sets of data in one chart.

Time series
Multiple data series
Relative series
Comparison series

Is multiple data series

To determine the correct answer to this question, let's analyze the options provided:

1) Time series: Time series charts are used to show data points that are measured over time. They typically display trends or patterns in the data over a specific period.

2) Multiple data series: This option refers to charts that display multiple sets of data on the same chart. Each data series is plotted using a different color or symbol, allowing for easy comparison between the different sets of data.

3) Relative series: This option does not accurately describe the concept of comparing sets of data in one chart. Relative series typically refers to comparing a data set to a benchmark or baseline to determine its relative performance.

4) Comparison series: This option accurately describes the purpose of comparing sets of data in one chart.

Based on the analysis, the correct answer is "Multiple data series."