D.30 Answers: Relationships between two quantitative variables
Answers to exercises in Sect. 33.6.
Answer to Exercise 33.1:
Linear, positive, very little variation (i.e. strong relationship).
Of note:
The observation in the bottom left
is very different from the rest of the data,
but still maintains the linear relationship.
Answer to Exercise 33.2:
Non-linear; higher wind speed related to higher DC output (in general);
a small to moderate amount of variation.
The DC output increases as wind speed increases,
but not linearly.
Answer to Exercise 33.3:
The relationship probably linear…
but a few observations at the top right look a bit different.
Variation seems to increase a little as the Age increases.
Of note::
A few observations in the top right of the scatterplot
seem to not follow the linear relationship.
Answer to Exercise 33.4:
Approximately linear; positive relationship;
variation seems to get larger for a larger number of cases.