Question 122·Medium·Command of Evidence
Average Daily Water Consumption Before and After a Citywide Conservation Program
| Customer Type | Before Program (Year 1) | After Program (Year 3) |
|---|---|---|
| Residential | 120 million gallons | 90 million gallons |
| Commercial | 65 million gallons | 58 million gallons |
| Industrial | 40 million gallons | 38 million gallons |
City officials stated, “Our voluntary conservation program was effective, particularly among households; it resulted in a significantly larger reduction in residential water use than in industrial water use.” Which statement based on the data in the table best supports the officials’ claim?
For command-of-evidence questions with a table, restate the claim and identify exactly which categories must be compared. Compute the relevant changes (differences or percentages) for those categories, then choose the option that most directly states the same relationship (e.g., “residential decreased more than industrial”) supported by the computed values.
Hints
Focus on what needs to be compared
The officials are making a claim about residential versus industrial water use. Focus on those two rows of the table.
Compute the changes
For residential and industrial customers, subtract the “After Program” value from the “Before Program” value to find each decrease.
Pick the statement that best supports the claim
Eliminate choices that don’t compare both residential and industrial decreases, even if the numbers in the statement are true.
Step-by-step Explanation
Identify what the officials are claiming
The officials claim the program was effective particularly among households and produced a significantly larger reduction in residential water use than in industrial water use.
So the best support must compare residential vs. industrial and focus on the size of the reduction.
Calculate the residential and industrial decreases
Compute each decrease from the table:
- Residential: million gallons
- Industrial: million gallons
Compare the decreases
Residential water use dropped by 30 million gallons, while industrial water use dropped by 2 million gallons. Since is much larger than , the data support the claim that the residential reduction was significantly larger.
Select the option that states that comparison
The statement that directly matches this comparison is: Residential customers reduced their daily water use much more than industrial customers did.