A manufacturing company operates three production lines: Line A, Line B, and Line C. The company tracks the number of defective units produced per 1,000 units. Last month, Line A produced 50,000 units with 200 defects, Line B produced 75,000 units with 450 defects, and Line C produced 40,000 units with 120 defects. Which production line has the lowest defect rate per thousand, and what is that rate?
- ALine A, 4.0 defects per thousand
- BLine C, 3.5 defects per thousand
- CLine B, 6.0 defects per thousand
- DLine C, 3.0 defects per thousand
Show answer & explanationAnswer & explanation
Correct answer: D. Line C, 3.0 defects per thousand
To find the defect rate per thousand, divide the number of defects by the total units produced, then multiply by 1,000. For Line A: (200 defects / 50,000 units) * 1,000 = 4 defects per thousand. For Line B: (450 defects / 75,000 units) * 1,000 = 6 defects per thousand. For Line C: (120 defects / 40,000 units) * 1,000 = 3 defects per thousand. Line C has the lowest defect rate at 3.0 defects per thousand.
Why the other options are wrong
- A. This is the defect rate for Line A, which is not the lowest.
- B. This option incorrectly calculates the defect rate for Line C.
- C. This is the defect rate for Line B, which is not the lowest.
Defect Rate Per Thousand
A quality control metric that quantifies the number of defective items produced for every 1,000 units manufactured. It helps in comparing the quality performance across different production processes or periods.
- Calculated as (Total Defects / Total Units) * 1000.
- Used for standardized comparison of quality.
- Lower rates indicate better quality control.
Memory trick: For quality, count defects per thousand, ensuring standards are sound.