Final answer:
Assign 100 percent to the most recent period when calculating trend percentages.
Step-by-step explanation:
The student should assign 100 percent to the most recent period when calculating trend percentages. This is because the most recent period represents the current state and serves as the reference point for calculating the percentage change in the other periods. Assigning 100 percent to the most recent period allows for easier comparison and analysis of the trend over time.