A graph question that asks you to support a claim tests whether the numbers show what the claim says. Read the claim first, and ask which change or comparison would support it. Then read the graph's title, axes, and key so you know what each value measures. For a fair comparison, use the same units and time period for each group you compare. Check every group the claim compares; true data can still miss the claim.
Hints
- Hint 1
The company is testing an energy-saving upgrade. Decide what kind of change would count as a benefit.
- Hint 2
Use the title, axes, and key to identify what the plotted values measure.
- Hint 3
Test the analyst's claim against all three buildings. Which values would you need to compare?
Step-by-step
Compare the electricity saved
Step 1Turn the claim into a comparison
An energy-saving upgrade is meant to reduce electricity use. To support the claim that Building B benefited the most from the upgrade, what should we measure? We need how much use fell, and most means comparing Building B's fall with Building A's and Building C's.
- Step 2
Calculate each building's drop
The title and axes show daily electricity use in kWh, and the key names each line. How much did use fall over the years shown in the graph, from 2019 to 2023? Building A went from 180 to 160, B from 230 to 140, and C from 200 to 150. Subtracting gives 20 for A, 90 for B, and 50 for C, in kWh per day.
- Step 3
Use the largest drop as evidence
Which sentence shows that Building B benefited the most from the upgrade? Because 90 kWh per day is greater than both 20 and 50, Building B saved more than either other building. The phrase a bigger drop than Building A or C gives that full comparison. Choice A.