Answer:
To calculate the marginal grade improvement (MGI) for each hour of studying, we'll use the following formula:
MGI = Grade Improvement / Additional Hours of Studying
Given:
Grade after 4 hours of studying = 80
Grade after 5 hours of studying = 90
Grade after 6 hours of studying = 93
Marginal Grade Improvement (MGI) for the 5th hour of studying:
MGI for the 5th hour = 90−80/5−4 = 10/1 = 10
Marginal Grade Improvement (MGI) for the 6th hour of studying:
MGI for the 6th hour = 93−90/6−5 = 3/1 = 3
Reasons for Diminishing Marginal Grade Improvement (MGI):
The MGI may be diminishing for several reasons:
Fatigue: As the students study for longer periods, they may experience fatigue, leading to reduced focus and productivity.
Saturation: After a certain point, additional studying may not result in significant improvements in understanding or retention of material.
Diminishing Returns: The initial hours of studying may have a greater impact on grade improvement compared to later hours, as the most crucial concepts are mastered first.
Overall, diminishing MGI suggests that there is an optimal amount of studying time beyond which additional hours may not yield proportional improvements in grades. Students need to balance studying with rest and other activities to maintain productivity and avoid burnout.
