What percentage of cars have known CO2 emissions?

• A. 82%
• B. 81%
• C. 83%
• D. 51%

Answer: (C)

Understanding data completeness and how to compute the share of records with a known value is what this question tests. To find the percentage of cars with known CO2 emissions, you count how many cars have a recorded CO2 value and divide by the total number of cars, then multiply by 100. This shows how complete the CO2 data is. In this dataset, 83% of cars have a CO2 emission value recorded, meaning 83 out of 100 cars have known CO2 emissions. For example, if there were 1,000 cars, about 830 would have a CO2 value. The other options would imply different levels of completeness, which don’t match the data. So 83% is the figure the dataset provides.