Reading a Data Table Under Time Pressure
A Science passage presents a table of enzyme activity (product formed, in micromoles per minute) at five temperatures for two enzyme variants, X and Y:
Temp (°C): 10, 20, 30, 40, 50 Variant X: 2, 8, 15, 9, 1 Variant Y: 1, 5, 12, 14, 3
A question asks: "Based on the table, which statement is best supported?" Choices: A) Variant X has a higher optimum temperature than Variant Y. B) Both variants show maximum activity at 30°C. C) Variant Y retains more activity at 50°C than Variant X does at 10°C. D) Activity for both variants increases steadily from 10°C to 50°C.
A student chooses B because "30 looks like the middle and both are high there."
1. Evaluate each answer choice against the table and identify the correct one.
Read the worked answer
Read the table column by column.
- A) X optimum higher than Y? X peaks at 30°C (15). Y peaks at 40°C (14). So Y's optimum is higher, not X's. A is false.
- B) Both max at 30°C? X maxes at 30 (15) ✓, but Y maxes at 40 (14), not 30 (12). B is false - the student's "middle looks high" reasoning is a trap; Y's 30-value is high but not its peak.
- C) Y at 50°C (3) vs X at 10°C (2)? 3 > 2, so Y at 50 retains more than X at 10. C is true.
- D) Steady increase 10→50? Both rise then fall (X: 2→8→15→9→1; Y: 1→5→12→14→3). D is false.
Correct answer: C. The student's error was pattern-matching ("middle = peak") instead of comparing each variant's actual maximum.
2. Explain the reading strategy that would have prevented the error on choice B, and describe how to handle a table item when two variants peak at different points.
Read the worked answer
Strategy: never infer a trend from position; read the actual numbers. For "optimum" or "maximum" questions, scan each row/column for its literal highest value and note the corresponding x-value.
Concrete method for this table:
- For each variant, circle the largest number and note its temperature. X → 15 at 30°C; Y → 14 at 40°C.
- Compare optima directly: 30 vs 40, so Y's optimum is higher.
- For "retains more" or cross-comparison choices (like C), pull the two specific cells named and compare only those - don't summarize the whole curve.
When two variants peak at different points, the table is testing whether you can resist a global summary ("both peak in the middle") and instead track each series independently. Also watch for choices that are directionally wrong (D) and for choices that reverse the comparison (A says X higher when it's Y). On timed ACT Science, the fastest safe habit is to verify each choice with one or two exact cell readings rather than trusting the visual shape of the numbers.