To title your graph, tap on the graph so that it is highlighted. Select Chart from the top menu and select Chart Options. Select Titles from the tabs. Click on the Labels button. Title your graph.

To label the X axis, select Category (x) axis. Title the axis as Time (min). Click OK.

You can enlarge your graph by clicking on a corner and dragging to the preferred size.

Save your Excel™ spreadsheet before closing for future analysis.