The x-axis is time in minutes going from zero to twenty in increments of five. The y-axis is the heart rate in beats per minute going from zero to one hundred and forty in increments of twenty. The heart rate of student A is indicated in red and that of B is indicated in blue. The heat beat of student A reaches a maximum of 100 beats at 6 minutes and then decreases. The heartbeat of student B reaches a maximum of 130 beats at 7 minutes and then decreases.