Answer: 400 calories per hour
Explanation:
Q: Tina recorded the number of calories she burned during a bike ride. The graph shows Tina’s calories burned, y, after x hours. If Tina rode her bike at a constant rate for the first three hours, what was Tina’s average calories burned, in calories per hour, between hour 0 and hour 3?
Expalanation: It is seen from the graph that her rate of burning calories increased to 1200 in the first three hours of riding and then remained constant for the rest of the period (2 extra hours).
Her rate of calorie use therefore would be given as: (total calorie used up) / (total hours spent riding for the period of usage)
This is given as: 1200 calories / 3 hours = 400 calories per hour.