1, ? Let's import a student's math report form and enter = round (average (B3: B 13), 1) in the average cell. As shown in the figure.

2, ? Select the cell range A2:B 13, and select Insert-Chart-Line Chart to display the line chart as shown below.

3, ? Now let's make a mean line, right-click the chart-select data pop-up dialog box, click the Add button to pop up the edit data series dialog box, and enter =Sheet3 in the series name! $A$ 14, enter =Sheet3! $B$ 14, click OK.

4, ? Right-click the data point with average score in the chart, and select Change Series Chart Type from the right-click menu to open the Change Chart Type dialog box to change the chart type with average score to a scatter chart. Click OK.

5, ? Select "Average Score" data point and select Layout-Error Lines-Other Error Lines to open a dialog box. Select horizontal error line, positive and negative deviation and wireless terminal. Select Error Amount as user-defined, set positive and negative error difference = 1 1 and negative error value = 1, click OK, click Line Color, set it as solid line, and select a color. Click OK to see the average dividing line.