Repeat Steps 2 through 4 to draw the remaining straight and curved lines on your inserted image to complete the scale drawing in Excel.

The Draw tab is not on Excel's ribbon by default. Learn how to enable, add and use the Draw tab and the various drawing tools in Excel.

To do so, click the Line tool and then hold down the Shift key while you click and drag to insert the line. Doing so forces Excel to draw a straight line between the two clicked points.

You can make a curved graph in Excel and Google Sheets using this tutorial. Learn how to convert sharp edges into smooth lines in a spreadsheet graph.