Final answer:
To add a point at 10:00 a.m., plot the coordinates (10, 7) on the graph. To add a point at 1:00 p.m., plot the coordinates (1, 0) on the graph.
Step-by-step explanation:
To add a point at 10:00 a.m., we need to plot the coordinates (10, 7) on the graph. This means that at 10:00 a.m., Lin was at an altitude of 7 meters.
To add a point at 1:00 p.m., we need to plot the coordinates (1, 0) on the graph. This means that at 1:00 p.m., Lin was at sea level, which is 0 meters in altitude.