What percentage of cars have known CO emissions?

• A. 83%
• B. 82%
• C. 81%
• D. 51%

Answer: (B)

Understanding how to read the proportion of cars with known CO emissions is essential. “Known” means a CO emission value has actually been recorded for that car. The percentage is found by dividing the number of cars with data by the total number of cars, then multiplying by 100.

If the result is 82%, that means 82 out of 100 cars have a CO emission value in the dataset, and 18 out of 100 do not. For a concrete example, with 50,000 cars, 82% known equals 41,000 with data and 9,000 without.

The other percentages would correspond to different amounts of missing data and wouldn’t match the data shown here, so 82% is the correct interpretation.