GMAT Focus EditionData InsightsMedium
A manufacturing company operates two production lines, Line A and Line B. The company tracks the number of defective units produced per 1,000 units. The data for the last month is: Line A: Total Units Produced = 50,000, Defective Units = 1,500 Line B: Total Units Produced = 75,000, Defective Units = 2,100 Which line has a lower defect rate per 1,000 units?
- ALine B
- BLine A
- CBoth lines have the same defect rate.
- DCannot be determined from the given information.
Show answer & explanationAnswer & explanation
Correct answer: A. Line B
To find the defect rate per 1,000 units, first calculate the defect rate as (Defective Units / Total Units Produced), then multiply by 1,000. Line A: (1,500 / 50,000) * 1,000 = 0.03 * 1,000 = 30 defects per 1,000 units. Line B: (2,100 / 75,000) * 1,000 = 0.028 * 1,000 = 28 defects per 1,000 units. Line B has a lower defect rate.
Why the other options are wrong
- B. Line A has a defect rate of 30 per 1,000 units.
- C. The defect rates are different.
- D. The defect rates can be determined from the given data.
Per-Thousand Rate
A per-thousand rate expresses the frequency of an event as a proportion of 1,000 units, useful for standardizing comparisons.
- Calculated as (Number of Events / Total Population) * 1,000.
- Common in quality control, epidemiology, and public health.
- Helps normalize data for populations of different sizes.
Memory trick: Defects Over Total, then Times a Thousand!