A chart or graph is a pictorial representation of data. Charts visually demonstrate the relationship between data that is easier to see rather than a series of numbers.

Each chart must have a data source which is the worksheet where the data is stored. The source is the data which is represented in the chart or graph. A data source has one or more series of data. Each data series is plotted on a graph or chart as a unit by itself ( columns on a column chart, a slices of pie on a pie chart, or a lines on a line chart, Chart Titles, legends, etc.).

A line chart can have more than one range of series values like a column chart, but unlike a pie chart which can only have one.

A data series has three components which are:

Series Values. These values are the actual data that is represented in the chart. A line chart can have more than one series values.

Series Name. The series name just identifies the series.

Category Values. The category values are the categories that the series values belong to.

A line chart compares values from several categories with a sequential order such as dates and times that occur at evenly spaced intervals.

To create a line chart enter the data below, select the data series as shown below.

On the Insert tab, Charts group, select Line Chart. (Select the first 2-D option.)

The following worksheet and chart illustrates the line chart. However, the chart needs work in order to make it a better representation of the data. The lines are too close and hard to distinguish.

Chart Tools is a contextual tab that appears when the chart is selected. The three tabs available are DESIGN, LAYOUT, and FORMAT.

These are the same three options available when formatting any type of chart.

The chart range is the data range from the worksheet.

The chart lines represent the series values.

The Legend is the box that identifies patterns or colors that are assigned to the series values or categories in a chart.

The Y-Axis scale is a range of data which Excel selects that best fits the data being represented on the Y-Axis.

The X-Axis represents each category value.

Chart Title is the name of the chart.

The Y-axis scale is a range of data which Excel selects that fits the data being represented on the Y-axis. In the example on the first page, Excel selected the scale 0 to 120 in intervals of 20. Excel selected the scale based on the data.

On the Chart Tools contextual tab, Layout, Axes group, select Axes, Primary Vertical Axis, and More Primary Vertical Axis Options.

The following is an illustration of the window.

The following window opens for the user to make changes in the Y-axis scale which will better fit the data values.

The following options are available:

Minimum Value is the lowest value on the Y-Axis. Excel will automatically set the lowest value for the user or it can be manually set.

Maximum Value is the largest value on the Y-Axis which is automatic, but the

user can manually change to another value.

Major Unit is the interval between values on the Y-Axis. Excel will automatically select the major unit; however, the user can manually change the major unit.

Minor Unit is the value that falls between two major units by intervals selected by Excel. This is also the tick mark intervals.

Major Tick Marks are extensions of the gridlines.

Minor Tick Marks can be selected by the user.

Horizontal Axis Crosses is the value point where the horizontal axis crosses the vertical axis.

The illustration below shows changes to the line chart after formatting the Y-Axis.

The Y-Axis Options were changed (Layout was also changed which is explained in the next column.) to the following:

Minimum value was changed to 70. The maximum value is 100. The major unit is 10 (70, 80, 90, 100), and the minor unit is 5. There are no minor or major tick marks displayed.

The above chart is a quick layout chart. On the Design tab, Chart Layouts group, there are 12 options available. Layout 5 was chosen for the chart layout. The illustration below shows the 12 options available for chart layouts.

Gridlines help the viewer determine the value of the chart line. Tick marks are the gridlines that extend past the chart to the number scale on the axes which helps the viewer associate the value with the line. Tick marks act like a line on a ruler.

To format the X-axis, select the X-axis and on the Chart Tools contextual tab, select Layout, Axis option, Primary Horizontal Axis, More Primary Horizontal Axis options. The following window will open.

The options available are:

Interval between Tick Marks . It defaults to 1. This means a tick mark will appear after each category value. If you change to intervals of 2, tick marks will appear after every other category value. The number that you key in determines how many categories are placed between the tick marks.

Interval between Labels which defaults to 1. If changed to two, only every other label on the X-axis is shown.

Label Distance from Axis just means how close the label values are to the axis. It defaults to 100. If the user changes to a lower number, the label values will be closer to the axis. If the user selects a larger number, there will be more space between the label values and the axis.

A line chart can be changed from a 2-D chart to a 3-D chart. Select the chart and the Chart Tools contextual tab appears. Select Change Chart Type, select 3-D Line (Line group last option). The following illustrates a 3-D line chart.

The 3-D chart rotation dialog box allows the user to change the X and Y axes rotation. Changing the axes rotation changes the appearance of the chart. The chart to the right

shows the line chart after the X and Y axes have been rotated.

The line chart X axis has been changed to a rotation of 40 degrees and the Y axis has been changed to 10 degrees. The perspective was changed to 25 degrees.

The following is 3-D rotation dialog box.

Perspective is the way in which objects appear to the eye. The perspective is the illusion that parts of a 3-D chart that are father away from you decrease in size. It is really a trick of the eye.

A legend is an object in an Excel chart that is used to identify which data markers represent each series value. It is a box that identifies the

Student Grading Scale

Student Grading Scale

patterns or colors that are assigned to the series values or categories in a chart.

To change the legend, select the Chart Tools contextual tab, Layout tab, Labels group, Legend. Click on the down arrow next to the word legend. The options available are:

Turn Off Legend; Show Legend at Right, Top, Left, Bottom; Overlay Legend at the Right or Left and More Legend options. ( The Overlay option can be a space-saving option.)

The illustration above shows the chart legend. You will notice the middle legend is in the edit mode. When in the edit mode, the line color and corresponding legend color can be changed. (Home tab, Font group, Fill Color which is the paint can.)

Most charts have 5 components. The 5 components include:

Chart Area which is the rectangular box containing the chart and all the other chart elements.

Chart Title is the title of the chart usually appearing at the top of the chart.

Plot Area contains the line chart. It is the rectangular area defined by the horizontal and vertical axes. It is the white space around the chart.

Data Markers represent the data values. The data markers are the lines.

Legend identifies the data markers.

An embedded chart is the default chart location. It is embedded next to the data used to create it. The advantage of an embedded chart is the data explaining the chart is next to the chart. It may help the viewer understand the data better.

A chart sheet is a chart devoted to the entire sheet. There are no data cells in the chart sheet. The advantage of a chart sheet is that detailed charts that need more space can be seen more clearly.

To move the embedded chart to a chart sheet, select the chart and on the Chart Tools contextual Design tab select the Location button. The Move Chart window opens for you to enter a Chart 1 Sheet. The user should rename the chart.

The chart styles are similar to the cell styles and the table styles. Chart colors and appearances can be changed by using the Chart Styles Library. There are 48 options on the Chart Style group. Click the line chart and select the Design tab on the Chart Tools contextual tab, click the down arrow on the Chart Styles group. It will display all 48 styles.

A chart is normally displayed inside a border box. Resizing a chart is the same procedure as resizing a graphic. Select the chart and the border box changes to the edit mode. While in the edit mode, there are sizing handles in the form of small dots which are used to resize the chart and the border. Place the insertion point over a set of the small dots. The insertion point changes to a double-headed arrow. At this point, the chart and its border can be enlarged or compressed.

The user can also move the chart inside its border. If you move the insertion point inside the border, it becomes a four-headed arrow. When it is a four-headed arrow, click on the outside edge of the chart and the edit box will appear. The user can now compress or enlarge the chart within the chart border.

Sometimes it is best to insert data labels so that the values are easier to read. A data label is text associated with a series value. The following are the steps to add data labels to the chart.

Select Chart (Chart will be in the edit mode.)

Layout Labels Group Data Labels

A well-designed chart is a simple chart. A line chart should only include 3 or 4 data series. The user should focus on the data rather than the embellishments of the chart.

Gridlines should be used to help the viewer understand the data. Too many gridlines can detract from the chart. Too few gridlines may make the chart hard to interpret.

Colors can be very helpful to distinguish one series values from another. However, too much color can detract from the chart. The default color options may not be the best choice. Select colors that complement the chart. Remember when choosing color know your audience. A colorful chart may not be helpful if a member of the audience is color blind.