Catch-can test: what does the lowest quartile refer to?

Catch-can test: what does the lowest quartile refer to?

• A. The quarter of cans with the lowest measured outputs.
• B. The quarter with the highest outputs.
• C. The middle half.
• D. The average of all cans.

Answer: (A)

Quartiles divide a set of measurements into four equal parts from smallest to largest. The lowest quartile is the bottom 25% of those measurements—the cans that show the smallest outputs. In a catch-can test, you’re ranking each can’s measured output, so the lowest quartile refers to the quarter with the smallest values. The top quartile would be the largest 25%, the middle half is the central 50% (the second and third quartiles), and the average is the mean, not a quartile.

Quartiles divide a set of measurements into four equal parts from smallest to largest. The lowest quartile is the bottom 25% of those measurements—the cans that show the smallest outputs. In a catch-can test, you’re ranking each can’s measured output, so the lowest quartile refers to the quarter with the smallest values. The top quartile would be the largest 25%, the middle half is the central 50% (the second and third quartiles), and the average is the mean, not a quartile.