Question 6.39

4. Global warming is due to increased concentrations of greenhouse gases such as carbon dioxide (). Here are data from the National Oceanic and Atmospheric Administration website (www.noaa.gov), where atmospheric is measured in parts per million per unit of volume. The data below were measured at the Mauna Loa Observatory:

315.98 324.62 336.78 352.90 368.14 387.35
Year 1959 1969 1979 1989 1999 2009

(You will revisit these data in Exercise 20.)

  1. Which is the explanatory variable?
  2. Make a scatterplot. Is the association between these variables positive or negative? Explain why you expect the relationship to have this direction.
  3. Describe the form and strength of the relationship.