A graph question that asks you to support a conclusion tests whether the numbers show every part of the claim. Read the conclusion first and separate its parts, then ask what data would support each part. Use the title, axes, and key to identify the groups and time periods, then compare their values. Check every reported range against the lowest and highest plotted values for that group in that period.
Hints
- Hint 1
Read the managers’ conclusion and separate what it says about pastry ordering from what it says about coffee ordering.
- Hint 2
The new board was installed after four weeks. Look for the redesign’s dividing line so you can group the weeks correctly.
- Hint 3
Find each line’s lowest and highest values on each side of the redesign. Do those ranges support both parts of the managers’ conclusion?
Step-by-step
Compare both lines before and after the redesign
Step 1Separate the claim’s two parts
Managers say the redesign increased pastry ordering but did not meaningfully change coffee ordering. What would show both parts? Pastry percentages should rise, while coffee percentages should stay near their old level. The standard board was used for four weeks, so compare weeks 1 through 4 with weeks 5 through 8.
- Step 2
Find the ranges for both lines
The graph tracks the percentage of orders that included a pastry and the percentage of orders that included coffee by week. Green is pastry, purple is coffee, and the dashed line marks the redesign. How do the ranges change across that line? Pastries are at 18% to 20% before the switch and 34% to 37% afterward, while coffee remains at 62% to 64% in both periods. That’s a higher range for pastries but the same range for coffee.
- Step 3
Check every range in the choices
Now check every range against both parts of the claim. The version with about 24–26% puts pastries too low, and the version saying the pastry percentage stays about 18–20% misses the rise. The version with coffee at about 55% by week 8 misreads its final value of 63%. The choice with pastries at about 34–37% afterward and coffee about 62–64% in both periods reports both patterns with the right numbers. Choice C.