A manufacturing company tracks defects per 1,000 units produced for four production lines (P, Q, R, S) over three quarters. The company defines 'high quality' as less than 5 defects per 1,000 units. A sortable table displays this data. To identify the most consistent high-quality line, one should sort the table first by 'Production Line' and then by which other column, and what calculation should be performed?
✓ Correct Answer: Option A
Consistency implies low variability. Sorting by 'Defects' allows easy identification of overall performance. Calculating the standard deviation per line directly measures consistency. A lower standard deviation signifies higher consistency.