The following scatterplot displays lung capacity (forced expiratory volume, measured in liters) vs. age (in years) for a sample of children:
1-3. Comment on the direction, strength, and form of the relationship between lung capacity and age. (Be sure to relate your comments to the context.)
The following scatterplot also incorporates information about whether the child is a smoker:
4. Do smokers tend to be older or younger than nonsmokers? Explain how you can tell from the graph.
5. For children of similar age, do smokers tend to have more or less lung capacity than nonsmokers? Explain how you can tell from the graph.

Question

The following scatterplot displays lung capacity (forced expiratory volume, measured in liters) vs. age (in years) for a sample of children:
  1-3. Comment on the direction, strength, and form of the relationship between lung capacity and age. (Be sure to relate your comments to the context.)
The following scatterplot also incorporates information about whether the child is a smoker:
  4. Do smokers tend to be older or younger than nonsmokers? Explain how you can tell from the graph.
5. For children of similar age, do smokers tend to have more or less lung capacity than nonsmokers? Explain how you can tell from the graph.

Quizplus · Accepted Answer

The Answer is 1-3. There is a moderately strong, positive, linear association between lung capacity and age for these children, meaning that the older a child is, the greater his or her lung capacity.
4. In general, smokers tend to be older than nonsmokers. This result can be seen from the scatterplot because the red dots tend to occur at the older ages (13, 16, and 18 years for example), whereas the majority of the black dots tend to occur at ages 13 years and younger.
5. For children of similar age, smokers tend to have less lung capacity than nonsmokers. This result can be seen in the graph because at any given age (e.g., 11, 12, or 16 years) the red dots tend to be below the black dots.

The Following Scatterplot Displays Lung Capacity (Forced Expiratory Volume, Measured