Making a Graph Using Microsoft Excel

 

1.                  Start Excel.

 

Entering Data

2.                  You will place the independent variable numbers in column A to be graphed on the x-axis and the dependent variable in column B to be graphed on the y-axis.

3.                  The values in column A must be equally spaced, e.g. 2, 4, 6 or 250, 500, 750) type the first (lowest) independent variable value in cell A1 and press "Enter".

4.                  In cell A2 type the second value and "Enter".

5.                  To have Excel fill in the rest of column A for you, use the mouse to put cursor in cell A1 and hold mouse button down while moving to cell A2.  Release mouse button to "select" the two cells.

6.                  Use the mouse to move cursor to bottom right corner of cell A2 so it changes from hollow cross to solid cross.

7.                  Press and hold the mouse button while moving cursor down to insert the desired data.  Release mouse button.

8.                  In column B enter your data that corresponds to the values in column A.

9.                  When all data is entered, use "Page Up" or mouse button to top of page and click mouse button in cell A1.

10.             Once you have all your data entered, select both columns of data and click on the small bar-graph icon at the top of the window.  This is the Chart Wizard.

 

 

 

 

 

 

 

 

 

 

 

11.             Select from the different types of charts/graphs available.  Choose the XY (Scatter) graph.  From the chart sub-types, choose the graph which shows the data points and connects them with a smooth line. 

12.             Click Next to see a sample of your graph.  Click Next again to continue.

 

 

 

 

 

 

13.             Click on the Titles Tab at the top of the open window to enter the Chart Title and the x- and y-axes titles.  Notice that as you type, your sample graph is updated to show the new titles. 

14.             Choose the Legend Tab at the top of the open window to choose placement of your legend.  For this graph, un-check Show Legend to remove the legend from your chart.

15.             Click Finish to see a completed graph.

 

Line of Best Fit

16.             The line Excel plots is connected data points.  For most science graphs a line of best fit is appropriate.

17.             To delete the line (not the data) click on it to highlight it.  Click Format on the menu bar and Selected Data Series... in the Line box click the None button and OK.  (Leave the data series highlighted.)

18.             To add the line of best fit click Chart on the menu bar and Add Trendline.

19.             If the data indicate a straight line choose Linear and OK.  If data indicate a curved line choose Logarithmic and OK.

 

Extrapolating Data

20.             Extrapolating data is a way to extend your trendline so that additional points can be predicted or an x- or y-intercept can be found.  To extend your trendline, select your trendline and from the Format menu, choose Selected Trendline.  Click on the options tab and then use the Forecast option to extend your line backwards or forwards. 

21.             If needed, check the box that says “Display equation on chart” to show the slope-intercept form of a linear equation.  (This will show you the exact y-intercept.)

 

Changing an Axis Scale

22.             Excel automatically chooses where your graph axes will begin and end.  You can change the scales of the axes to better fit your data. To change an axis scale, double click on the axis and choose Scale from the Tabs at the top of the open window.  Type in the new minimum and/or new maximum.

 

Printing the Graph

23.             To print the graph click in an empty space on the graph to highlight it.  Click on the printer icon (fourth or fifth from the left) or click File, Print, OK.  This will print your graph only.