By selecting all three columns of data, you can select the type of chart from Excel's Insert tab. The most useful selection is a bar chart, because it allows you to format the second series as a line.

To make a smooth curved line graph in Excel, follow these steps- Enter your data in the spreadsheet and select it to make a graph. Go to the Insert tab and insert a 2-D line graph.

How to Find the Slope of a Line on an Excel Graph. In math and statistics, you may occasionally need to calculate the slope of a line generated by coordinates in the (x,y) format.