To animate a line graph in PowerPoint, you need to open the slide, draw the Graph add the labels and then animate the graph as explained here.

We show you how to create a Histogram chart in Microsoft PowerPoint. A Histogram is a graphical representation that shows frequency data.

Launch PowerPoint and open the presentation in which you want to make a graph. Click the "Insert" tab and locate the "Illustrations" section.

Insert different values and go back and view the line plot on your slide in PowerPoint. Close the Chart in the Excel window when you are satisfied with the result.