Air quality

Air quality#

Air quality measurements were collected in a random sample of \({{ params.country_capitals }}\) country capitals in \({{ params.year_1 }}\), and then again but in a different set of cities in \({{ params.year_2 }}\). We would like to use these data to compare average air quality between the two years.

Part 1#

Should we use a paired or non-paired test? Explain your reasoning.

Answer Section#

  • Paired, because data are recorded in the same cities at two different time points, and the air quality in a city at one point is not independent of the air quality in the same city at another time point.

  • Paired, because data are recorded in different cities at two different time points, and the air quality in a city at one point is independent of the air quality in another city at another time point.

  • Non-paired, since air quality is influenced by many varying factors each year, making each year’s data independent.

  • Non-paired, because the measurements are from different, non-corresponding cities each year so, the air quality in a city at one point is independent of the air quality in another city at another time point.

Attribution#

Problem is from the OpenIntro Statistics textbook, licensed under the CC-BY 4.0 license.
Image representing the Creative Commons 4.0 BY license.