Graphs and Charts Study Notes

Chapter 16: Graphs and Charts

Learning Objectives

  • Produce a graph or chart from given data.

  • Select data to produce a graph/chart.

  • Select the graph or chart type to match the required purpose and meet the needs of the audience.

  • Label the graph or chart appropriately.

  • Add a second data series to the chart, as necessary.

  • Add a second axis to the chart, as necessary.

  • Change the maximum and minimum values of an axis to appropriate values.

  • Enhance the appearance of the graph and chart.

Introduction to Producing Graphs or Charts for Data

  • Data can be represented in various formats including tables, graphs, or charts.

  • Spreadsheet applications are utilized to perform complex calculations on data and to create graphs and charts for analyzing trends and patterns.

Creating a Graph or Chart Using a Spreadsheet

Steps to Create a Graph or Chart in Excel:

  1. Select a range of cells containing the required data, ensuring to include both column and row tables in the selection.

  2. Click on the "Insert" tab, then navigate to the Charts group.

  • Users can also view suggested charts by navigating to "Recommended Charts".

Selecting Data to Produce Graph or Chart

Contiguous vs. Non-Contiguous Data:

  • Contiguous Data: Refers to data that are adjacent to one another in a table.

    • Example of Contiguous Data: A set of numbers listed together in a column or row.

  • Non-Contiguous Data: Refers to data that are not adjacent or are scattered throughout the table.

    • Example of Non-Contiguous Data: Data points selected from different locations within a spreadsheet.

Types of Graphs or Charts

  1. Column Chart

    • Represents data using vertical bars.

    • Used to compare values across single or multiple categories.

  2. Line Chart

    • Shows the changing trends in data over a period of time.

    • Data points are connected by lines.

  3. Pie Chart

    • Shows comparisons using proportions, representing parts of a whole.

    • Data is illustrated as slices of a pie, where each data value represents one slice of the pie.

  4. Bar Chart

    • Represents data in the form of horizontal bars.

    • Similar to a column chart, but with horizontal columns, ideal for displaying multiple values when data labels are larger.

  5. Area Chart

    • Similar to a line chart but with the area under the lines filled in.

    • Used to focus on different sets of data over a period.

  6. Scatter Chart

    • Shows the comparison or correlation between pairs of values on the x-axis and y-axis.

    • Also referred to as an XY chart.

Elements of Graphs or Charts

Chart Element Purposes:

  1. Axes

    • X-axis (Category Axis): The horizontal axis of the chart mainly used for displaying names of different categories of data.

    • Y-axis (Value Axis): The vertical axis showing data values.

    • In a 2D chart, there are two axes: x-axis and y-axis; in a 3D chart, there are three axes: x-axis, y-axis, and z-axis.

    • The unit of measurement displayed is called the Scale.

  2. Axis Title

    • A label assigned to each axis based on the corresponding data series.

  3. Chart Title

    • The heading designated for the chart.

  4. Data Label or Sector Label

    • A label associated with a small part of the chart or graph, allowing user editing for clarity.

  5. Data Table

    • A label permitting users to view the data table alongside the chart or graph, placed below the chart.

  6. Error Bars

    • Small bars aiding the user in analyzing the error margins for the plotted data.

  7. Gridlines

    • Lines indicating the exact values of each data point.

  8. Legend

    • Helps in identifying specific data series, where each series has a color-code for easy reference.

  9. Trendlines

    • A line revealing trends such as increases or decreases in values.

Labelling Graphs or Charts

Steps to Label a Chart:

  1. Click on the chart.

  2. Click on the Chart Elements icon.

  3. Select or deselect specific elements using their respective check boxes.

Working with a Pie Chart

  • To highlight a specific sector of a pie chart, click on it and drag it outwards from the remaining chart.

Formatting Data Values in Pie Chart

  • Options include label options and text options presenting various choices such as:

    • Series Name

    • Point Name

    • Data Values or Percentages

    • Show Leader Lines

Adding a Data Series

  • A data series consists of data entered in rows or columns in a data table that is subsequently plotted on a chart.

  • To add a data series:

    1. Click anywhere on the chart.

    2. Drag the handles on the data table to include the new data series.

    3. The chart will automatically update to include the new series.

Quiz Coverage

  • Chapter 16 encompasses producing graphs or charts from data, including practical applications such as creating and manipulating various chart types and elements.