IGCSE ICT 0417 - Graphs and Charts

16. Adding a Second Data Series

This section explains how to add a second data series to a graph or chart in spreadsheet software like Microsoft Excel or Google Sheets. This is useful for comparing two different sets of data on the same visual representation.

Why add a second data series?

Adding a second data series allows you to:

• Compare two different datasets.
• Show trends of two related variables.
• Visualize the relationship between two sets of information.

Example Scenario

Imagine you are tracking the sales of two different products over a period of months. You can create a graph with one series for each product to easily compare their performance.

Steps to Add a Second Data Series (using Excel/Google Sheets as an example)

1. Enter Your Data: Ensure your data is organized in two columns. The first column will represent the categories (e.g., months), and the subsequent columns will contain the data for each series (e.g., Sales for Product A, Sales for Product B).
2. Select the Data: Select all the data you want to include in the graph, including the category labels and the data for both series.
3. Insert a Chart: Go to the 'Insert' tab and choose the type of chart you want (e.g., Line chart, Column chart).
4. Add the Second Series:
   • Right-click on the chart and select 'Select Data'.
   • In the 'Select Data Source' dialog box, you will see a list of your data series.
   • Click the 'Add' button to add the second data series.
   • In the 'Series name' field, enter a descriptive name for the second series (e.g., 'Product B Sales').
   • Ensure the 'Series values' field correctly points to the data range for the second series.
   • Click 'OK'.
5. Customize the Chart: You can now customize the chart further by adjusting titles, labels, colors, and legends to make it clear and easy to understand.

Example Table

Month	Product A Sales	Product B Sales
January	100	80
February	120	90
March	150	110
April	130	100

Figure: Suggested diagram: A line chart showing 'Month' on the X-axis and 'Product A Sales' and 'Product B Sales' on the Y-axis, with different colored lines for each product.

Important Considerations

When adding a second data series, it's crucial to:

• Use distinct colors for each series to avoid confusion.
• Include a clear legend that identifies each series.
• Ensure the scales on the Y-axis are appropriate for both data series.
• Choose a chart type that effectively visualizes the relationship between the two datasets (e.g., line chart for trends over time, column chart for comparisons).