How to make a graph using Excel:

I. To enter data: open Excel and click on "Excel Workbook" template
1) Enter data in column. The first column you enter (i.e., the left column) Excel will graph on the x-axis.

II. To graph data:

1) Select (highlight) the data columns you want to graph. Select the numbers, not the column headings.
2) Under <Insert> menu, select "chart".
3) Click on "xy scatter" -- this gives you a graph without the best-fit line.
Keep clicking "next" until "finish" is the only choice. (Then choose "finish".)
4) Select (click on) the graph, then under <Chart> menu, select "add trendline" -- this puts the best-fit line on the graph.
5) Click on the line. Make sure the trendline is selected, not just the graph.
6) Under <format> menu, choose "selected trendline", then "options", then toggle "Display equation on chart" and "display R-squared value on chart". -- This puts the equation of the line on the graph and the R² value. R² is a measure of how "linear" your line is.
R² = 0: your points are scattered and there is no linear trend whatsoever.
R² = 1: your points form a perfect line.

III. To label axes and add title
1) Select (highlight) the graph.
2) Under <Chart> menu, choose "chart options". This will take you to a screen where you can enter text for axes and a title.