Average Rate of Change

Question

Mr. Adam grades 68 papers in 2.5 hours on Tuesday. He grades 82 papers in 3 hours on Wednesday

Answer 1

rate of grading 1 = 68 / 2.5 = 27.2 papers per hour

rate of grading 2 = 82 / 3 = 27.33 papers per hour

change = 27.33 - 27.2 = 0.13 papers per hour increase

rate of increase = 0.13 / 27.2 = 0.478%

Answer 2

(82 - 68) / (3 - 2.5) = ?